Twig tried his best not to focus on Vihaan as the Nilgiri marten draped his sinuous form across their couch and scribbled into his notebook for prolonged periods of time. The mustelid stopped only rarely and momentarily to tap the eraser of his pencil pensively against the tip of his angular snoot. Though he would never actively snoop through his roommate’s possessions, the deer mouse had caught glimpses of the other anthro’s omnipresent pad on occasion. As an engineer himself, Twig was certainly no stranger to electrical schematics and mechanical assemblies, but the scrawl was an incomprehensible mess to him. There were many components he immediately recognized the utility of, but they were mixed with chemical notations and organic diagrams in confounding ways. Equations butted up against anatomical sketches which overlapped with seemingly meaningless sentence fragments that surely held some degree of significance, otherwise his friend wouldn’t obsess over them so much.

The rodent’s gaze rolled over the other male. Vihaan was in his early 30s. At 5’4” tall and weighing about 135 pounds he towered over his murine companion’s comparatively minute size. He had a sleek, toned body with a long, winding torso which caused him to move with an excess of fluidity and grace. His soft, fluffy tail was nearly as long as his body was tall. Most of his pelt was a deep, coffee brown with a glossy sheen, so dark that was almost black. The underside of his chin, in contrast, was a stark white, but the ashen fur quickly faded along his throat to a swath of crisp, vibrant orange. His nose, inner ears, and paw pads were charcoal black and his eyes were reflective pools of ink, as enigmatic as the mammal himself.

Vihaan noticed the inquisitive mouse staring.

“Yes, little mouse?” The reclining marten inquired with a cocked brow. His voice held a perturbed edge, but the pet name he called his housemate and the amusement that played at the edge of his muzzle told that he enjoyed teasing Twig’s insatiable interest in his work. 

The smaller fur felt his ears begin to tinge red with warmth as he blushed at being caught. 

“When are you going to tell me what this secret project you are working on is?” The murine pried. He posed the question many times in many ways, ever eager to learn just what Vihaan was up to. Unfortunately, he usually received a vague answer at best, if he even got any response at all.

“When it’s done. You’ll find out when the rest of the world does,” his mustelid friend deflected with a dismissive wave.

“But I want to know now,” the rodent replied with an exaggerated whine.

“I signed an NDA. Everything I do now is on a need-to-know basis. Unless you’re on the project, I’m afraid that I can’t tell you a single thing about it,” explained the marten as he slowly closed his notebook with a self-satisfied smile.

Twig sighed and fought the urge to harrumph and cross his arms with displeasure. The bushy-tailed anthro’s smug smirk turned subtly predatory.

“That said,” he continued, “we do happen to need a new lab assistant to help us test the project. You don’t need any experience with the type of work we do. In fact, it might be better if you didn’t. If you are really serious about finding out just what it is I spend forty to sixty hours a week on, I can probably fast-track you onto the team. Of course...you’ll be working for me.”

The deer mouse briefly wondered what had happened to the previous lab assistant (it did seem like Vihaan went through an awful lot of them as of late), but after months of curiosity gnawing away at him, Twig couldn’t help but jump at the chance to satiate his nosy nature.

“When can I start?”

A few excruciatingly slow days later the pair drove together to the mustelid’s workplace. The rodent was bouncing with anticipation the entire ride there. Twig was nearly blinded upon entering the building. It was clearly a recent construction with a bright and modern minimalist interior. What little furniture was in the massive lobby was primarily sleek, shiny chrome and alabaster-colored vinyl. A series of mammals of all species were introduced to him as they made their way across the ground floor to the HR office to get the new employee’s mountain of paperwork out of the way. Their faces, names, and scents all blended together in a confusing blur as he was pulled along.

In addition to all of the standard forms that he was used to filling out, Twig was required to sign an array of medical and liability waivers, legal agreements to secrecy, and other equally unsettling contracts. He was assured by a business-suited doe and his lab-coated companion, that it was all perfectly normal for the experimental and confidential nature of the work, he shouldn’t be overly concerned by the veritable library of documentation. The other furs’ reassuring smiles put the rodent enough at ease to commit his squiggly signature to paper after paper, all of which were promptly scanned and filed away with an almost unbelievable efficiency.

Afterward, the deer mouse was ushered into an express elevator that lowered the duo deep underground. Twig had no idea how far down they had gone, but the freefall pace of the cubicle caused his stomach to feel like it was trying to escape his own muzzle. When they at last exited, the minute rodent found himself in a room that appeared to be a strange mix between an eccentric inventor’s workshop and a hospital. On one side of the massive chamber were several long counters that were cluttered with tools of all sorts, gadgets, spools of multi-colored wires, calculators, monitors, tablets, microscopes, and other odds and ends. Whiteboards with marker scribblings that looked to be enlarged versions of those in Vihaan’s notebook filled nearly every inch of wall.

The other side of an imaginary dividing line down the center of the room stood in stark contrast. It was clean and unadorned. A few tidy island counters with some cabinets, a computer, and a few medical supplies were arranged near a immense glass enclosure, some ten feet to a side. In the center of the clear-walled structure there was a sleek steel bed with one end raised to create a slight recline adorned with only a small cushioned headrest. It wasn’t dissimilar to what he would expect to find in an operating room, leading Twig to conclude that it was an observation chamber of some sort. The sterile scent of rubbing alcohol was joined by the smell of oil and just the slightest whiff of ozone.

Twig tilted his head to the side curiously upon seeing the strangely split laboratory. As far as he was aware, his dark-furred friend was merely a highly talented engineer and wondered what medical equipment was doing in his workspace. It could be a space shared with a second team of researchers and creators, he supposed, but for such an obviously wealthy company to force its developers to share workspaces when they had an entire building that stretched as far underground as it clawed at the sky struck him as silly. He pondered if maybe the marten created more medical equipment than he had previously assumed.

As if sensing his new employee’s confusion, the Vihaan cleared his throat to get the rodent’s attention.

“I am a biomedical engineer. I create new technology to help advance our understanding of the body and fix illness and injury without the need for drugs as well as innovating new ways for technology and biology to interact. As my new assistant, you’ll be helping me test my prototypes-” Twig’s eyes widened in sudden alarm. “Don’t worry, I won’t need to make you sick or injure you. You’ll be helping in the ‘proof-of-concept’ phase of my newest design, where I see if my current project merits looking deeper into practical application or if it should just be scrapped entirely.”

The mustelid rummaged about while Twig nodded along with his explanation. As he spoke, the mouse detected a ghost of smile twitch at the edges of his roommate’s muzzle, and unless his mind was playing tricks on him, the slinky anthro’s glassy black eyes grew subtly predacious.
Eventually, the engineer found what he was searching for and slipped it into his pocket. The item held in his claws in that brief moment was too small for the other fur to make out before it went out of sight. 

“We will be testing my latest invention today. We already had you take a comprehensive pre-hire physical, so we have your baseline measurements recorded and can jump right in,” Vihaan expounded, proudly brandishing the tiny, glinting object.

He pulled his smartphone from the pocket of his lab coat and proceeded to give the screen a series of deliberate taps. There was a faint hiss and whirl of an unseen mechanism while one wall of the glass enclosure slid a several feet to the side, allowing access within.

“Please strip down and step inside,” Vihaan directed with a subtle sensual leer, still more heard than seen. “You can leave your clothes on the counter there.”

Twig had never been a modest rodent, and his friend had seen him in nothing other than his hide on more than one occasion. The power dynamic made him mildly self-conscious, however, so he felt his cheeks and ears warm as he began to undress and released a meek, involuntary squeak. The 35-year-old deer mouse kept in decent shape he wasn’t at all embarrassed of his 4’5” body. He was 85 pounds with a slim to average build. His well-groomed coat was mostly light brown, but the fur around the outside of his ears was a smooth, rich chocolate color. The murine’s underbelly from just beneath his nose to the tip of his tail was a creamy white. His nose, inner ears, paws, and the underside of his tail were all a fleshy pink. Sparkling forest green eyes complemented his earthen pelt and he had pronounced buckteeth protruding down over his bottom lip. His slender tail was just shy of four and a half feet long and tended to stand somewhat erect behind him. Unlike many mammals, Twig’s testicles were primarily internal, and appeared merely as taught lumps between his thighs just below a very short sheath.

The mouse set aside his bundle of clothes with a slight shiver, then stepped inside the clear vault. He hopped up to sit on the exam table provided and squeaked again, more sharply this time as his rump touched the chill metal. He swished his tail apprehensively this way and that while curiously twitching his whiskers, a habit that always gave away when he was nervous. Vihaan followed him in, twisting his sinuous torso alluringly as he walked.

“The first thing I’ll need from you, Twig, is a DNA sample. Please paw off for me and ejaculate into this,” he held forth a small, sealable container as he spoke.

The rodent’s face grew even warmer as he tentatively plucked the dish from the taller fur’s grasp. “Here? Now?” He inquired with a furtive fidget. An exhibitionist streak ran deep in the murine which occasionally reared its head and the thought of being studied while he pleasured himself struck an unnervingly stimulating chord within him.

“Of course, little mouse. Now hurry, we haven’t got all day,” the mustelid responded, barely concealing his entertained smirk as he caught a whiff of arousal in the air. “Do you need...motivational material? We have videos prepared if they will help.”

While the naked other antho briefly considered the enticing offer, the thought of watching porn while his friend observed him was somehow more embarrassing than a clinical and necessary masturabatory session. He wrestled with the idea before ultimately declining with a quick shake of his head. The thought of being examined so thoroughly and closely was already having its effect on the deer mouse. He would need no further inspiration as he felt a tingling warmth flood his loins. His fur bristled as he involuntarily shuddered with delight while he bashfully lowered a paw to this crotch and kneaded his plump sheath and fuzzy testicle-bulges.

It didn’t take long for his phallus to stir. Twig’s erection immediately entreated out of its furry confines. The rigid length extended to its full, respectful (given the mouse’s slight stature) four and a half inches. The hardened flesh was a deeper shade of salmon than the rest of the rodent’s exposed skin and solid in color. It glistened in the fluorescent lighting with its own natural moisture. Watery pre beaded at its tip and trickled down his and over his claws. The rodent grabbed his hardness with a deft paw and rapidly drummed his digits along its trembling underside, sensitizing the needy organ. He massaged his penis with a practiced enthusiasm, scarcely chastened by his friend watchful gaze.

“When was the last time you pawed off?” Vihaan asked casually, licking his lips with a sharp flick of his tongue. His voice held a slight huskiness to it, and an unmistakable scent of arousal wafted from the marten.

Twig was about to respond, but suddenly unleashed a sharp squeak as his nimble fingers found a delightful spot just beneath his throbbing tip.

“Three days,” he eventually huffed as his his paw picked up a steady rhythm stroking his twitching cock. The masturbating rodent occasionally challenged himself to go a few days without cumming. Sometimes he even had the self-control to edge himself during the wait and make the resulting, eventual orgasm that much more potent and enjoyable.

“That long? What’s the longest you’ve ever gone without playing with yourself?” The mustelid eagerly asked. His pants were clearly tented now as he observed his roommate toy with himself.

“About a week,” Twig answered meekly.

“A whole week? Why would you do that to yourself?” The marten pressed, cocking his head with fascination. 

“I was with that opossum at the time- you probably remember the one- with the piercings. He liked to control me. It was pretty intense when he would finally allow me to cum,” the mouse responded, his humiliation gradually evaporating as his arousal swelled. The reminder of the steel cage his lover used to clasp tightly around his sheath and the hefty weight of the lock caused a surge of lust within him. He remembered the dominant male spinning the key about his sylphlike digit, taunting Twig while the horny murine pleasured him repeatedly.

“Ever think you could do even longer than that?” Vihaan questioned, keeping his remarks in the realm of the sexual as to not distract his cohort from his task.

“I’ve thought about trying, but have you ever gone a week without cumming? You’ll do anything to paw by the fifth day!” The mouse exclaimed as a spurt of pre gushed forth from his member and drizzled onto the polished steel between his thighs.

Twig’s breath began to hitch and his abdomened spasmed and tightened. The warm, tingling in his testes grew. As his slick paw continued to glide over his needy length, now completely coated in his own pre, he knew it wouldn’t be long until he finally came. The deer mouse allowed a soft whimpering, moan to escape his lips and rolled his head back, approaching rapture. He forced himself be ready to catch his sample. With a final squeak, ecstasy gripped his body and he tensed. The masturbating fur quickly angled his pulsating hardness into the dish and climaxed. He sprayed the glass vessel with his seed. Ropes of rodent emissions splattered across the container in several, surprisingly large bursts, glazing it with pearlescent strands.

The remaining vestiges of Twig’s orgasm cascaded over the back of his hairless paw in glittering rivers. The heady aroma of his ejaculate hung heavy in the air. Out of habit the now-lethargic rodent lazily licked his digits clean. He reveled for a brief moment in the sweet, salty treat that coated his claws. His chest heaved as his muscles relaxed. The spent male slumped back and let his head press against the cushion provided, laying flat and still. He puffed until his breath steadied again and then weakly held the container of cooling mouse spunk toward his friend. The dark-pelted mustelid engineer shrewdly snatched it away, seemingly uncaring if he got his paws sticky in the process. He whisked it off toward a particular instrument in the larger chamber and fed the sample into a small slot in its side. After fiddling with some settings on whatever program was open on the computer attached to the strange equipment, Vihaan promptly returned.

The Nilgiri marten withdrew a pill bottle from his lab coat pocket. Inside it was a small, silver sphere, about the size of a pencil-eraser.

“This is my newest experient. It looks like traditional medicine, but is really a cluster of microscopic robots that will enter your body and, hopefully successfully, perform a variety of remotely programmable applications. The tasks they can perform is should be limited only by our ingenuity, but right now we are focused on practical concerns in medicine and psychology such as improved healing of injuries and curing illnesses and aiding in...well, let’s call it self-control. It needs to be calibrated to the user, hence the DNA. Honestly, a blood, saliva, or even a fur sample would have been enough,” the inventor admitted with no amount of regret in his voice, “but I figured that this would be a lot more fun for both of us. The program is adjusting to your specific body chemistry now. Any moment now we will be able to administer and test it. And of course I can and will remove any trace of it from your body once the test phase is done. We don’t want a corporate spy to kidnap you for it after all.”

Vihaan pulled out his phone again and stared intently at the screen for a few seconds. After a brief pause it beeped excitedly and the mustelid used his thumb claws to type out a rapid series of inputs. Without warning the smooth bit of metal began to buzz and rattle about of its own accord. The marten opened the bottle and fished out the vibrating object with the tip of his claw and held it up between himself and Twig.

“Do I just swallow it like a pill?” His lab assistant ventured as he lazily examined the miniscule bauble in his post-orgasmic haze with a wary eye.

“Not quite,” Vihaan said with a snort of amusement, carefully laying down his project on a nearby countertop. He sauntered over to a cabinet and withdrew a box of medical gloves and a squeeze bottle full of clear fluid. “The best method, we’ve found, is to administer it rectally.” He winked as he snapped a rubber glove tightly over his paw and began to slick his fingers with what must have been lubricant from the bottle.

“You’re joking.”

“I’m quite serious, I assure you. Now spread your legs and lift your hips for me,” the marten said with lascivious smirk. He rubbed his slippery digits together. Satisfied with their moist sheen, he trotted back next to his companion.

Twig’s face grew hot again with renewed embarrassment as he hoisted his waist and flicked his tail off the side where it drooped over the edge of the exam table, revealing the tight, pink ring of flesh just beneath its base. His erection hadn’t yet fully subsided and it oozed the final traces of his most recent ejaculation over his sheath, which was now uncomfortably close the handsome engineer’s snoot. Vihaan stood at the base of the table between the mouse’s spread ankles, serpentine figure towering over the rodent’s comparatively smaller form.

The rodent shivered as he felt the cold, wet finger prod his entrance almost teasingly, lubricating his hole with practiced precision. It traced a quick, skillful circle around the pucker before finally beginning to wriggle its way in. Twig gasped at the chill touch, but became used to the sensation in short order as Vihaan glided his slender, greased finger inside. He twisted it this way and that as he steadily pressed forth until he made it in the base of his knuckle. The anthro beckoned against the sweet spot within his smaller friend, causing him to squirm and shiver as he was expertly loosened. A second digit worked its way in, more easily than the first, and the Nilgiri marten scissored them apart. He continually withdrew and reinserted the invading members to gradually reduce the taut pressure of the other fur’s orifice.

Much to his chagrin, Twig released a series of involuntary squeaks and groans as he fought his urge to writhe with bliss and failed. His groin stirred once more and he felt his cock begin to plump again, twitching back to life.

“I haven’t even inserted the device yet,” Vihaan commented with a raised brow.

“You’re enjoying this,” the rodent accused in a raspy voice.

“Actually it looks like you are enjoying this, little mouse,” the marten snickered. “But I guess we can’t just entertain ourselves all day.” He withdrew his dextrous paw and for a brief instant Twig’s stretched hole felt empty. The sensation didn’t last long, however, for within seconds the sinuous anthro’s claws returned, this time with the metallic suppository on the tip of his rubber-clad finger. The digits thrust in deep and quick, inserting the object far within him.

As it came in contact with his insides, the murine felt the item resonate with warmth and energy. A pleasurable ripple reverberated within him as the technological marvel came alive and the microscopic robots energized within his cells. Being as close as they were to his prostate, this had the immediate and lasting sensation as though a vibrating butt-plug was working its magic on him, and he stifled an embarrassing moan of delight.

“It certainly sounds like all is going well so far,” the marten remarked, taking far longer than he needed to to remove his fingers from inside his friend’s heat. He tauntingly dragged them along the other anthro’s pleasure center as he finally did. Despite the slenderness of his friend’s paw, he felt the absence of the digits and longed for their swift return.

Twig shuddered and tried to control his breathing as the gratifying sensation in his ass failed to abate.

“So, if you aren’t going to hurt me or make me sick to see if these little guys fix it, what are we going to do?” The mouse questioned, fidgeting.

“We’re going to test the final major function I told you about: aiding in one’s self-control...among a few other things. Though it should be noted that I said that I wasn’t going to injure you, not that I wasn’t going to hurt you. There most definitely is, technically speaking, a difference,” Vihaan elucidated.

Twig swallowed nervously and tried to force a chuckle as his housemate removed his glove and picked up his phone off of the counter he had left it on. He began to tap away and swipe smoothly along the screen until a monitor set into the wall over his shoulder flickered on. It displayed simple green against a black backdrop text reading “336:00:00.” Immediately, it began to count down.

335:59:59.

335:59:58.

335:59:57.

“That is two weeks. During this two week period you will not be allowed to experience the pleasure of orgasm,” the marten informed him.

Twig suddenly jerked due to an unexpected flare in the pleasant buzzing of near his prostate and felt his half-erect phallus throb with delight at the sensation. 

“How can these robots stop me from pawing off?” He asked incredulously. With the wonderful way the insertion had made him feel thus far, it seemed far more likely that he would be masturbating regularly, rather than be prevented from doing so.

“If you don’t believe me, feel free to give it a try. But I promise you won’t be able to,” the anthro stated simply with a confident grin.

With the stimulation over the past several minutes, Twig had experienced a long enough refractory that he was willing to have another go. He released a delighted squeak as he grabbed his shaft once more and began to pump away at the cum-slick inches of tumescent flesh. He reached a practiced rhythm with his strokes quickly and sighed and wiggled while the nanobots undulated within him. After only a couple of minutes of massaging his sensitive rod, the mouse’s breathing again grew erratic. He quaked and groaned as he approached the edge of orgasm. Just as he was about to climax, however, his muscles startlingly seized. A sudden and lasting pain coursed through his minute form, causing him to wrack and spasm and jolt.

The mouse felt his fur stand on end and his whiskers twitch with a charged aura in the immediate aftermath of the shock that originated inside of him. While the zap affected the whole of him at first, the majority of its effects were centered on the murine’s crotch. A sharp pain had quickly shot through his penis, followed shortly by a lingering static caress that ran the length of of his phallus like an electric finger teasing his skin. It caused waves of tingling numbness to pulse along Twig’s shaft and in his testes. His length, though eager for release, was anesthetized by the lost feeling and steadily deflated, leaving an unfulfilled, ache in his balls. As the rodent regained control of his faculties he noticed the countdown on the monitor had suddenly flashed from vibrant green numbers to an otherwise blank, angry crimson screen. It beeped and, as it reverted to its former appearance, the emerald numbers started counting down again from 336 hours; second by excruciating second.

Vihaan smiled cruelly at the denied rodent.

“Well, now we know that that function works,” he affirmed. “Enjoy the next two weeks, Twig.”

The deer mouse fur fought to keep his jaw from dropping to the floor. Two weeks was a long time. A very long time. He squirmed, still incredibly horny from his lack of orgasm despite the electrifying results of his recent attempt. The vibration behind his groin was still strongest and most centralized near his prostate, but it had gently spread to be a steady, low-frequency hum that was almost imperceptible throughout his extremities.  

“Uh...I think I’d like to opt out now,” Twig ventured, dazed. The electric current that assaulted his cock hadn’t stopped. He now felt as though there was a halo of lightning that started at the base of his member which slowly drew upward toward his tip and back down again, like a stroking paw. As it reached its apex the voltage seemed to rise, prickling his flesh more sharply and causing small yelps of surprise and twinges of pain. Then, as the invisible loop fell so too did his awareness of it, only for it to catch him off guard again seconds later. He quickly learned to steel himself for the unending spikes of scintillating power.

“Nonsense, little mouse! You signed a contract that you cannot choose to void without my approval and we only just started testing,” the mustelid commented wickedly. “Let’s try out a few other features. These are more, benign. I promise. I should be able to trick your body into feeling sensations that don’t correlate with reality. Tell me what you feel after I initiate each one.”

The engineer tapped a specific code into his phone and the smaller anthro felt a wave of warmth wash over him like he had suddenly stepped into steaming sauna. Inside of 30 seconds he was nearly panting from the imagined heat and humidity and managed to articulate as much to his friend and employer.

“Good. Good.”

A few more calculated taps across the keypad and the rodent’s teeth were chattering as they would if he were standing naked, enduring an artic blast. Shivering, he drew himself into a tight ball and tried to warm his paws with his breath to no avail.

“This is so intense,” he stammered.

“This is nothing yet. That was just checking the see the speed that you’d recognize the temperature change. Don’t worry, I can’t actually freeze you or fry you- that is just how you perceive it. I assure you that your actual body temperature is the same as it always is. Here is the real test. Tell me what you experience.”

Twig fidgeted as he suddenly felt a familiar sensation. He writhed and moaned while his tight ring felt as though it were drawn onto an object. He quickly discerned that the nanobots were making him feel like was steadily being penetrated by a massive penis. The length of the imaginary cock was tapered and smooth as it slowly slid in and stretched him, sinking inch after into him. It was a buck, from the size and shape of it (a species of anthro Vihaan knew very well that his friend favored), and slick as though it were thoroughly lubed and ready. Being an intangible sensation rather than a physical thing, there was no limit to its length or girth, and the not knowing just how deep the powerful phallus could be driven into him made the rodent to squirm needfully. The mouse gasped and huffed, crying out with enjoyment. His own maleness quivered once more, dribbling a glistening strand of pre.

“Come on, Twig. Tell me what you experience,” the marten instructed wryly. “For science.”

“You know what I feel!” he sputtered.

“Do I? You’d better describe it so I can make some notes.”

“Vihaan...It feels so...big- it’s still going in!” The murine whined, voice raw and husky.

“Come now, little mouse. I didn’t get a cocktail of degrees to be called Vihaan. We’re at work...Master will do nicely,” he commanded, absently massaging his bulge: his intoxicating scent of arousal suffused the air.

“It...it’s definitely a deer- ah! It’s throbbing in-inside me, Master. I can actually feel it shooting pre! It has to be at least a foot long. So thick...it just keep g-getting wider as it goes in, Master!”

Just as the rodent began to shyly describe the cock buried deep within him, struggling to form coherent sentences and blushing as he added awkward ancillary “Master” when appropriate, it changed motion. The turgid cervine length started to feel as if it were withdrawing to just its pointed tip and then, without warning, thrust back in deep again. The speed picked up and soon it was pistoning in and out of his ass. It was joined by the addition of a heavy, warm furred sac smacking repeatedly against his rump with each great jab that ran across his prostate. He could actually smell the domineering musk of an aggressive, dominant buck looming over him. Feel his breath on his neck.

“You wouldn’t believe the amount of code I wrote for this to function, Twig,” Vihaan chuckled. “But wait- there’s more!”

The electric sensation along mouse’s rigid cock suddenly abated and was replaced by a new sensation. It felt as if his shaft was enveloped in a highly skilled, moist maw. He could feel the heat and an enthusiastic, gifted tongue gliding along his length. If he were blindfolded, he would’ve sworn that he was being fellated by an expert. The wet, hot tongue rolled tantalizingly along his rod. He felt the playful tickle of a carefully drawn fang across his slick shaft. His drew uneven breaths and he rolled his head back in relaxation while on the precipice of release.

Twig’s eyes shot open, however, as dawned on him what was going to happen. He tried to prevent his coming orgasm by sheer force of will, but the velvet muzzle he sensed around his member and the ceaseless ramming his abused hole was receiving was too much for him to fight. Just as he was about to burst all of the satisfying sensations abruptly stopped and painful lightning arced through him again. Apathetic numbness settled into his loins, stifling his potential climax.

When the spasms from the brief shock subsided, what small amount of semen his body managed to muster before his orgasm was lost; dripping unsatisfyingly from his thrumming erection. His head lolled about in a haze of arousal, frustration, and pain. The tormenting electric ring returned. Climbing. Stinging. Subsiding. Repeating. The rodent groggily glanced over to the monitor, which was glaring red once more as its timer ticked back to the start.

335:59:59.

335:59:58.

335:59:57.

He looked over to Vihaan who smirked and lashed his bushy tail. The marten sniggered with a few more decisive taps on his phone. After he typed a few final things into his keypad he set the small device down. “Voice command mode: Activate,” he declared clearly.

“Voice authorization recognized. Vocal commands initiated,” responded a monotone computerized voice from several unseen speakers throughout the room.

“Just a bit more light testing and we can wrap up for today. We can always get into more serious trials tomorrow,” the mustelid commented. “Restrain: Position one!”

Twig instantly felt a peculiar sensation. There was a tremor to his muscles and then his body started to move without his consent. As if they forced back by a powerful anthro and chained in place, his wrists flung out and back, almost slamming his back flat against the table. He wrestled and fought, twisting his torso this way and that, but soon his ankles followed suit. His knees were raised up and slightly bent outward fully exposing his sheath and revealing his tailhole again. The mouse was stuck fast, spread out and completely vulnerable on the exam table. A paralyzing lethargy crept from the hum of the nanobots in his body and spread throughout his limbs leaving him able to feel normally but be unable to move. While his appendages remained tense and steadfastly in place his ability to struggle effectively ended.

“The nanite are releasing imperceptible electric impulses to stimulate your muscles into performing certain motions. We’re still a bit rough on the precision, so I won’t be able to control you quite like a puppet yet. But this seems good enough,” Vihaan explained, casually shrugging off his lab coat to reveal the tight-fitting dress shirt underneath. “You’re helpless against anything I would want to do to you now.”

He continued to strip as he meandered his way closer in a snaking path. His sinuous body exaggerated the sway of each step. The Nilgiri marten untucked and unbuttoned his shirt before slipping it off and casting it aside to reveal his upper body. The vibrant splotch of color that enveloped the front of his upper torso, Twig could see, also covered his inner arms and biceps to the elbows, but gave way to the much darker fur of the majority of his pelt just above his navel at a triangular point. Combined with the natural fullness of his fur, it gave the illusion of broadening his chest.

He unbuckled his belt, slid his pants down, and kicked them aside to be left striding forward in only his underwear. He continued toward his captive lab assistant until his crotch was eye-level with where the mouse was forced to recline. He wore warm-black briefs without any fly or piping that hugged his form tightly, revealing every contour of his sheath through the taut material as surely fur would, including his obviously engorged sheath and hefty sac, which created an attractive, round pouch in the front of the speedos. A faint, nylon sheen winked across the solid-colored fabric in the sharp lighting mirroring the gloss to Vihaan’s rich fluff to the point that Twig had difficulty telling exactly where his friend’s pelt ended and his underwear began. An alluring musk of sweat and sex emanated from the pouch of the briefs. Sharing a house with him, the rodent had scented his friend’s arousal before, but with its source being so close to his sensitive snoot (his whiskers were practically grazing the sheer fabric), it was potent and overpowering.

“Do you want the override code, pet?” Vihaan asked, doing well to control the hoarseness of his tone. “You can use it to end the experiment and walk out of here right now. But if you refuse it, I’m not going to offer it again until our work is done. It could take weeks, if not months, of…intense experimentation,” he warned, voice wavering with lust.

Twig scarcely hesitated before erratically shaking his head. 

“Pull down my underwear then, before I make you do it, little mouse,” the Nilgiri marten ordered with a huff.

The captive murine immediately complied. Drunk with want, he stuck his nose into his friend’s plush, carob-colored fur. His large front teeth had to search through the soft coat to find the waist of the speedos. After a few failed attempts he managed to nip at the elastic holding the garment to his boss’s lithe form and hook it onto his oversized incisor. Once his bite was secure, he tugged the fabric down. The material fought his attempts and edged downward in small bursts, at one point catching frustratingly on the mustelid’s rigid length until the mouse was able to adjust his pull and allow his friend’s leaking erection spring free. Out in the open, his shaft extended a bit over six inches beyond his plump, fuzzy sheath and was a fleshy marble of various shades of ebony. Over its final inch it smoothly narrowed to a rounded point, causing Twig’s to pine for the organ to hilt him. His turgid rod already oozed rivulets of pre and was trembling with need after he had spent the past several minutes debasing the rodent.

Vihaan moved one paw to the deer mouse’s head and wrapped his claws through the now-tangled fur at the back of the rodent’s skull. Twig opened his maw and took the marten’s hardness into his muzzle. Heat radiated from the mustelid’s swollen penis and Twig felt the salty splash of watery precum against his throat. The engineer unceremoniously thrust his hips forward until his willing prisoner’s nose was buried deep in his pubic fur and inhaling his scent, nearly choking the smaller anthro in the process as he held him there tight.

Enthralled by his soon-to-be lover’s pheromones, the eager mouse rolled his tongue along the underside of the hard cock and groaned with delight as he savored every inch of flesh the dominant fur had to treat him with. The mustelid shimmied sideways until he was behind the headrest of the exam table and Twig’s head was forced to roll back over the edge with his chin forming a perfectly straight line with his neck. His numb limbs prevented him from going anywhere and he was endlessly aroused by being utterly at his master’s mercy. His own cock jumped and twitched, having failed to receive a proper release twice now. The pleasant buzzing near his prostate had yet to show any signs of stopping.

Vihaan withdrew his phallus until just the very tip brushed the mouse’s bottom lip. He leaked a trickle of pre against the rodent’s lips, who greedily ran his tongue across them to catch it. Then he suddenly slid back into the base, causing his bound friend to gag. He began to piston his hips, mating with the squirming anthro’s ravaged throat while unleashing predatory snarls. His sac smacked Twig’s snoot with each thrust. From sharing a home with all-too-thin walls with the attractive marten, Twig knew that Vihaan loved to completely dominate his mates with loud, feral affirmations of his lust. Today was no different. The Nilgiri growled, moaned, and hissed as he bucked away. His thrumming shaft casually emitted wave after wave of hot pre, sloshing into his friend’s ready muzzle.

The dominant fur loomed over his slave’s vulnerable form, bending his sinuous body over the smaller mammal. He supported his upper torso by grabbing the murine’s legs and pressing his weight onto him. He gave the mouse’s denied length and teasing flicker of his practiced tongue. Twig shamelessly whined as he felt the pleasing brush of warmth and wetness against his member. His raw throat quivered around Vihaan’s coal-colored rod.

After a couple of minutes of mercilessly humping into his subordinate's mouth, Vihaan withdrew, chest heaving with exertion. His lover was left likewise panting.

“Restrain: Position two!” The taller fur huffed as he absently groomed some out of place fur that had ruffled up while he mated with Twig’s muzzle.

The numbness in the mouse’s extremities unexpectedly subsided and Twig could waggle his claws again for a brief moment. However, the microscopic machines in his body usurped control of his limbs once more, and like being tugged along by awkward, invisible marionette strings his arms and legs moved without his conscious input. He flopped over onto his stomach with his knees bent under him and splayed widely. The mouse’s arms were outstretched and his upper chest was pressed hard against the exam table. His hindquarters were presented prominently, and with his tail erect as normal, his tight ring was openly exposed. There was still a faint sheen of lube to his hole after the initial insertion of the nanites.

Twig’s cheek was flattened against the cold steel of the exam table he felt and the cool air caress his vulnerable entrance. The pulsing buzz of the machine inside of him and the incomplete orgasm from the sensation of being taken from behind earlier made him yearn for more. The mouse’s pink cock hung aching between his thighs, liberally drooling rodent seed. He panted and wriggled, and his toe claws curled in anticipation.

Vihaan slunk behind him, languidly stroking his own shaft as he went. In a smooth motion he snatched the bottle of lube from the counter and coated his maleness. He mixed the slick lube in with Twig’s saliva. The dark fur on his nape, spine and tail were bristling with a feral lust as he aligned his tapered tip with the other anthro’s tailhole. With a fierce hiss he plunged in deep until where his flesh met his sheath butted up against the mouse’s orifice all in one thrust, eliciting a squeak from the rodent that steadily trailed off into a wanton moan. Twig could scarcely fidget due to his bondage. He was stuck as surely as if he were tightly bound in ropes in chains.

With one paw the marten fondled the mouse’s hardness, teasingly running his claws roughly along its tremoring length. It combined with the ebbing and flowing of the electric current to threaten to push him over the edge again and give him another surge of pain and numbness to ruin any potential climax.

The domineering mustelid then started to crawl over his hostage. He perched atop his prone pet, claws holding him in place with his weight completely on him. Twig could feel their sharp pinch as they dug into his pelt, but didn’t quite break his skin. The marten arched his back and bucked wildly, slamming his engorged length into the mouse’s abused hole again and again. His submissive clenched down around the invading member, causing Vihaan to pre a continuous stream into his lover. His jabs were quick and vicious. He ground his meat deep into his friend with each pass. The mouse’s breath hitched and he bit his lip with pleasure as his roommate continued to pick up steam and huffed hotly into his large, round ear. Twig flipped down his ears down submissively and Vihaan took the opportunity to bite down on his scruff, exerting his dominance in a far more primal way than he did with the clinical mastery he had displayed over the course of the day.

Finally the marten felt his sac draw up and his abdomen muscles tighten as he approached orgasm. With a primal growl he buried himself to the hilt and bared his fangs, unleashing a torrent of cum into his plaything. His hips jerked and his body was wracked with pleasure as thick jets of spunk erupted from his cock and splattered his lover’s insides. Gasping, Vihaan relaxed. He let his body relax and draped himself over the still forcibly tense Twig. His erection slowly softened enough to slip from the mouse’s stretched ring.

Exhausted, but still needy, the rodent felt empty without his master in him and whimpered. The seed that sloshed about in him leaked from his presented hole, wetting the fur on the back of his thighs.

“This test lasts two weeks?” The deer mouse ventured weakly, his voice wavering.

“The initial phase does, yes,” the Vihaan responded between pants, finally rolling off of the murine. He milked his phallus of the final traces of his orgasm and held his paw absently toward Twig’s muzzle for him lick it clean. “Looking forward to being my lab assistant? I hope you know I’ll have to punish you with a shock everytime you...misbehave, little mouse.”

Already drained but still very horny, the rodent managed a feeble nod.

With a cruel smirk, Vihaan suddenly gripped Twig’s shaft and stroked half a dozen times. The mouse’s eyes widened in pleasure and fear as he felt a familiar feeling building in his loins.

335:59:59.

335:59:58.

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