The brothers decide they need to have a way to counteract their mating cycles if they're ever in an emergency. To do this Donnie comes up with a series of experiments to put his brothers through to help him collect data on how they react and what makes them tick while in their heats. But the sights and sounds of his brother's going through the experiments may be too much for Donnie to handle. Can he keep calm and continue putting his brothers through the experiments? Or will he give in to the thoughts that are starting to creep into his mind?

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Despite doing his best to remain professional, Donnie could not help but shift nervously as he watched his brothers step into his lab. He knew what was going to happen, he'd spent the last several weeks planning it and getting ready but…..that didn't make it any less awkward.

Mikey seemed to know what he was thinking, no surprise from the most empathetic brother. “Relax bro. We trust you, sides; it’s all for science. Right?”

Donnie swallowed nervously but nodded. “Y-yeah.”

It wasn't a lie. If his experiments were a success it would help him understand so much more about how their brains and bodies worried. But…..it was still awkward. Donnie remained silent as Leo spoke. “Why don't….you show us what we need to do Donnie?”

Yes, instructions; those were a good distractions. Blinking for a moment Donnie quickly moved over to one of the workbenches which was covered in alien tech. behind him he could feel his brothers moving with him, crowding in a bit closer than before. Turning to face them Donnie spoke, doing his best to keep his nervous out of his voice. “You’ll need to put these on first.” As he spoke Donnie reached down and picked up one of the small technologically rings that sat on the workbench. “They’re in ‘passive' mode right now. So you can just press the button.”

As he was speaking Donnie thumbed the button making the ring open. “And then you just put it on and close It.” continuing the demonstration Donnie slipped the ring around his neck before closing it; collaring himself. For a few moments his brothers looked at him wearily. Then Raph spoke. “Last time we wore those collars the triceratons made us fight each other. You sure they’re safe?”

Donnie nodded, at the same time pulling his collar off. “Yeah. They're safe. I removed the components that delivered the electric shocks. Plus ill have the remote instead of them.”

Still Raph looked unsure. “So….why do we need them?”

Opening his mouth to respond Donnie was cut off my Mikey who let out a small giggle. “Cause Donnie’s kinky as fuck and he wants to see us collared.” more giggles followed his words.

Donnie blushed, his face heating up rapidly from Mikey’s comment. Nevertheless he answered his brother’s question. “I’ve modified them to monitor your life signs as well as your brain activity. Without them, I can't get the readings I need. Also…..”

Donnie’s voice trailed off again as he found himself unsure of how to word what he wanted to say. It wasn't that he didn't trust his brothers. But…..once they were ‘under the effects’ he wasn't sure how willing they'd be to follow his orders. Besides measuring vitals and brain activity the collars had another purpose, to allow him to remotely control his brothers so he could continue with the experiments. Also if one of them got loose he could stop them from escaping or hurting one another.

But Leo saved him from having to respond, the oldest turtle’s voice sounding calm and confident as he spoke. “I trust Donnie’s judgment. If he says we need the collars, then they’re necessary.”

As he spoke Leo moved, stepping forward and taking one of the other collars that still lay on the bench. In a single motion Leo slipped the collar on, pausing for a moment to adjust it’s tighten slightly before closing it. Mikey followed suit a moment later. As he did so he turned to look at Donnie. “Does this please you master?”

Again Donnie blushed. He knew Mikey was trying to diffuse the tension, and also possibly to distract himself from his nerves; but…

Looking to Raph Donnie squirmed. He hadn't hidden the collars from them. The very first time he'd brought up the experiments he'd mentioned their necessity. It was true, without them the experiment wouldn't work. He needed the collar’s tech and processing power to gather the data. Without it the experiments would take months to perform. In front of him Raph huffed, no doubt still bothered by the idea of the collars. Again Mikey spoke. “Awww, is big tough Raphie scared to collared by Donnie? Afraid you'll like not being in charge?”

Raph’s temple twitched in annoyance and anger. “I ain't scared. Just…..” huffing again Raph moved forward, taking the collar Donnie held before slipping it over his neck and closing it. As he did so he growled to Donnie. “This had better word egghead. I won’t do this again.”

Donnie swallowed nervously but nodded. He'd run a few small scale tests. Each time the collars had worked perfectly. With all three collars secured Donnie moved, reaching down to pick up a small remote that sat on the workbench before pressing one of the small buttons on its surface. Instantly there was audible clicking sound as the collars locked, preventing their removal. A moment later they let out a soft hiss as the sensors and electronics began to power up. Taking a deep breath Donnie continued. “Now if you'll follow me”

Gesturing for his brothers to follow Donnie quickly led them through his lab and into an adjoining room. Again he felt a wave of nerves was through him. Inside the room, which was quite spacious; threw medical beds had been setup. In the middle of the room a small table sat covered with a sheet while several objects sat on the sheets surface. Above them a large devise hung down from the ceiling, its movable and retractable arms curled up against it as it was not in use.

Nervously moving towards the nearest bed Donnie had been about to speak when again Mikey cut him off. “I volunteer.”

Before Donnie could respond Mikey took the lead, hopping onto the bed and stretching out, his hands going behind his head in a relaxed and exaggerated manner. “Like this master?”

Again Donnie blushed, feeling his face heat up at Mikey’s words. “Um…..well…..actually…..”

Bending down slightly Donnie picked up the thick leather restraints which hung from the sides of the bed frames. Taking a deep breath he spoke, doing his best to sound calm and not embarrassed. “I need your arms to be at your sides.”

Mikey chuckled, sticking his tongue out in a playful manner. “Awww, but this way is so much more….sensual.” the last word came out huskily and seductive. But despite this Mikey moved, doing as Donnie had asked and putting his arms by his sides. Slipping the leather restraints round his brothers wrists Donnie quickly secured them before moving down to the foot of the bed and doing the same with Mikey’s feet. Once his brother’s limbs were secure he moved, pulling out the pillow he'd placed under the bed before moving to put it under his brother's head. As he did so Mikey smiled appreciably. “Thanks.”

Donnie nodded his voice stuttering slightly. “d-don't mention it.”

Turning to look at his brothers Donnie found that Leo and Raph were already moving, heading to the remaining beds. Moving towards his next closest brother Donnie bit his lip, doing his best to keep his hands from shaking as he quickly restrained Raph’s wrists and legs before providing him with a pillow as he had done for Mikey. As he did so Raph growled. “This better all be absolutely necessary. I agreed to this so it would help. Not so you could get your rocks off playing mad scientist.”

Despite the nerves he was feeling Donnie felt a small fire of defiance bristle in his stomach at Raph’s words. Pulling the restraints a bit tighter than he needed to, Donnie smirked slightly as his brother who glared up at him. “It is Raphael. I’m not some pervert who gets off on this. It is for a purely medical purpose I assure you.”

Raph remained silent, shifting slightly; no doubt testing the limits of how much he could move while restrained. After a few moments he muttered to himself. “Whatever.”

Producing another pillow Donnie quickly moved on to Leo. The oldest turtle had an odd expression on his face. Partially of nerves and partially of excitement; if the sight of his already swelling pouch was any indication. Remaining silent on his observation Donnie quickly secured Leo’s wrists and ankles, noting that as he pulled the restraints tight Leo’s pouch visibly pulsed and throbbed with excitement. All the while Leo remained silent, seeming to avoid Donnie’s gaze as he put the pillow under his brother’s head.

Moving towards the table in the middle of the room Donnie quickly gathered up the next item he'd need, before returning to his brother’s beds. As he leaned over to secure the blindfold Raph growled warningly. “What did I say?"

Again Donnie huffed in defiance. “Turtles are natural competitive. If you see the others you'll try to prove you're better. That will ruin the results and make this whole experiment pointless.” as he spoke he quickly secured Raph’s blindfold before returning to the table. Now came the important part.

Picking up one of the three syringes Donnie spoke to his brothers. “Now, I’m going to inject each of you with a serum that I’ve specially concocted so it will send all three of you in a temporary heat for a few hours. The dosages vary but the selection of who gets what is random.”

Testing the syringe to make sure it was working Donnie moved towards Leo. Quickly swabbing Leo’s arm, Donnie made short work of the injection. As he did so he could not help but note that Leo’s collar was already registering and increase in heartbeat and breathing. Next came Raph who remained silent this time as Donnie gave him his injection. Lastly came…..

Leaning over Michelangelo, Donnie could see his smaller brother shaking slightly. Not from anticipation but from fear. The smallest brother had always had a fear of needles. And no doubt the idea of being blindfolded and helpless and about to be injected was causing him a feeling of anxiety. Luckily he knew what to do to calm Mikey.

Gently he reached out, allowing his hand to gently stroke Mikey’s arm. At first Mikey jerked slightly. But Donnie ignored the movement, continuing to gently stroke his brother's arm while at the same time letting out a soft hum. Then suddenly he moved the hand that was gently stroking suddenly pinching Mikey’s arm while at the same time the needle vanished into Mikey’s skin.

Quickly injecting the serum into his brother before removing the needle before he had a chance to react. Patting his brother’s arm Donnie smiled as Mikey grumbled. “Some bedside manner bro.”

Returning to the desk in the middle of the room Donnie spoke as he took a seat. “Now we wait for it to take effect. Then we'll continue.”

To his right Leo groaned softly. “Think….I’m feeling it already.”

Glancing over Donnie silently agreed. The sight of his brother’s rapidly growing organ coming into view. A moment later the computer monitor in front of him confirmed his observation. Showing that Leo’s heartbeat had indeed increased while his brain waves were starting to rise. Leo was indeed starting to feel the effects. But unknown to him he'd only been given a quarter dose of the serum. Jotting down a note about how Leo was the first to react, Donnie waited as the minutes ticked by.

If his calculations were right in 5 minutes his brothers should all be under the effects of the serum. So for now there was nothing for him to do but wait. Unsurprisingly it was Raph who started to feel the effects next. Donnie watched, an odd sort of rush washing through him as he listened to Raph’s deep panting and grunting. A moment later the red banded turtle’s pouch retracted, allowing his large organ to slip free and rapidly grow to its full length.

Turning his attention to his youngest brother Donnie waited. He remained silent, watching and Mikey twisted and squirmed slightly in his restraints. He knew it wouldn't be long now. Like Raph Mikey was panting, little beads of sweat forming along his forehead and he groaned and squirmed. A moment later he gave in, his pouch retracting and allowing his organ to slip free. Glancing at the clock on the computer screen Donnie made a few quick notes, detailing how each turtle had reacted despite their varying dosages.

When he was done, he moved. Pressing a button on the computer and making the machine hanging from the ceiling, whir to life as he stood up. Making his way to Leo, Donnie watched as the machine he'd spent the last few weeks building came to life; slowly lowering itself down the from the ceiling while one of its metallic arms extended a small plastic tube at the end.

Once the machine was in place Donnie went to work. Quickly he unhooked the plastic tube from the metal arm, making sure the thinner flexible tubes were still in place before turning his attention to his brother. There was no denying Leo’s arousal. Even as he stood there Donnie could see Leo’s fully erect cock throbbing and pulsing visible, almost demanding attention. Reaching out Donnie touched his brother’s organ, a slight shudder running through him as Leo let out a ragged grunt and struggled against the restraints, his hips trying to thrust upwards into Donnie’s grip. 

Doing his best to ignore his brother, Donnie went to work. As quickly as he could he set about slipping the plastic tube over his brother’s organ. Again Leo moaned, his one a bit softer as the soft silicon entrance to the tube slipped over his tip before slowly engulfing his entire organ. Once the tub was firmly placed over Leo's organ Donnie adjusted a small knob, noting how Leo let out a deep shuddering purr as the air was sucked out of the tube with a soft hiss, encasing his throbbing organ inside. 

It was an odd feeling that filled him as he stepped back from his brother. If he was honest he felt in some ways like a mad scientist. He'd drugged his brothers, strapped then down and was running experiments on them; a very mad scientist thing to do. But on the other hand…..

Shaken from those thought by the sound of Raph’s grunting Leo did his best to push those thoughts away. He wasn't some mad scientist. He'd gotten his brother’s consent, even come up with a form for his brothers to fill out so he would know exactly what they were and weren’t ok with him doing. Busying himself with readying Raphael Donnie could not help but blush again as, just like with Leo Raph groaned loudly as his hand wrapped around Raph’s organ.

Unconsciously Donnie bit his lip. Unsurprisingly Raph was the most well endowed of his brothers, a fact that was on full display as Raph’s hit and hard organ throbbed and pulsed in Donnie’s grip. In the back of his mind Donnie made himself a mental note, noting how Raph’s organ felt almost hot to touch, and how a few mall dribbles of precum were already dribbling down his shaft; indicating Raph’s excitement. Just like with Leo Donnie quickly worked, encasing his brother’s organ with the plastic tubing, securing the silicon entrance before sucking the oxygen out of the tube.

Again Raph grunted, his cock throbbing and pulsing again as the tube became secure and snug around his base. But As Donnie’s hands left his brother’s body Raph growled. A deep low rumbling growl that made goose bumps erupts along Donnie’s arms and neck. For a moment he found himself frozen, his nostrils flaring slightly as the sudden rush of musk and sweat that his brother let off. The scent filled him, making a small ember of want flare up inside him. He remembered Raph’s scent; he'd smelled it many times before. Raph paired off with him a lot during their heats, not always but often enough. 

But a metal clinking sound pulled him from his mind, making him turn away from Raphael as the metal arm for Mikey came to a stop, ready and waiting for him. Shaking his head to clear it Donnie moved, his first few steps feeling like they took a bit more effort than usual. Like the others Mikey let out a deep groan as Donnie’s fingers gently wrapped around his shaft. Unlike the others though, Mikey’s moan was punctuated by a deep churr which made his chest vibrate deeply. Donnie bit his lip, aware at how dry his mouth seemed to have gone. As quickly as he could he got Mikey’s tube in place, another churr slipping from Mikey as the tube hiss securely in place around his cock.

As quickly as he could Donnie moved away from his brothers and back to his desk. Dropping himself into his chair Donnie forced himself to focus on the computer screen, noting that unsurprisingly his brother’s heart rates and brain activity had jumped again in anticipation of what was to happen next. Taking a deep breath Donnie forced himself to breath, trying to ignore the dregs of Raph’s musk as he started the next phase of the experiment. For the moment the sound of the machine drowned out his brothers moaning and grunting, providing him a brief moment of respite. But a moment later the machine began to work, the powerful suction making the silicon lining of the tubes contract and spasm for a moment before allowing a small bit of air in, making it relax before repeating the action over and over and over.

If he was honest the machine he'd built was actually very similar to the machine human’s used to milk cows, except…….he'd hooked it up to his brothers…..not a cow

Despite his best attempts at remaining professional, Donnie could not stop the blush that sprang up as the noises his brothers were making grew louder.
His eyes drifted up, leaving the computer monitor, which was showing the exact reaction he'd expected his brothers to have and instead settled on Raph who was in front of him. Unconsciously he bit his lip, watching as Raph struggled against the restraints holding him back. The machine was working perfectly, the rhythmic sucking and releasing of air making the silicone lining of the tube caressing and working Raph’s wanting organ.

Against his will Donnie recalled when he'd tested the machine himself. He'd gone through a few different designs of the machine, and each time he'd tested them on himself. He'd done his best to remain professional, measuring the pleasure he was feeling so he could refine the machine to its best working form that did what he needed it to do while making his brothers feel as good as possible. And now his brothers were experiencing the final result, a machine that felt nearly as good as a mouth but would never tire or slow. And judging from the way all three of them were moaning, grunting and straining against the restraints, they were enjoying the end result of his work.

Even as he watched Raph’s cock throbbed and pulsed from the repeated suction. Glancing down at the computer monitor Donnie noted how erratic Raph’s brain waves were getting, a sure sign of his rapidly approaching climax. From his spot on the bed Raph grunted and moaned, the sounds becoming rougher and more ragged as the pleasure continued to grow and grow. Donnie found himself watching his largest brother, taking in everything Raph was going through, committing it to memory for his notes afterwards.

He watched as Raph struggled and strained against his restraints, his hands clenching into fists as he struggled to move. His toes curled and uncurled from the pleasure and beads of sweat hard formed and were now glistening across his body like small jewels along his skin which occasionally twitched involuntarily. But it was the smell rolling off Raph’s quivering body that was the most shocking. The smell was almost impossible to describe, a deep earthy sweaty musk which seemed to fill Donnie’s nostrils and lungs, clouding his mind and making an unwelcome whimper of want slip from his lips. Of all his brothers he loved Raph’s scent most, it was the one he could identify the quickest, matching the aggressive turtle’s personality almost per-

But Donnie found himself pulled from his half addled thoughts as Raph jerked and grunted, a deep rumbling echoing half growl half churr erupting from his mouth as his climax began. Donnie watched as Raph’s cock swelled, seeming to grow larger for a split second before his seed erupted fourth. Donnie watch, fascinated and for a minute Raph’s first load flowed from his organ, filling the tube for a moment. But a split second later the warm fresh cum vanished, sucked away by the machine and put into a small tank for storage and analysis.

But one load wasn't all Raph had. Donnie watched entranced as a second, and finally a third load of cum erupted from Raph’s cock. Filling the tube a little less each time before being whisked away by the machine. All the while Raph grunted and churred, no doubt having one of the best orgasms he'd ever had in his life. Donnie watched, his mouth having suddenly become very dry as his brother spasmed and twitched from the pleasure. After several moments Raph groaned, his muscles relaxing, his head going back to rest against the pillow and he panted and tried to catch his breath.

The change in his brother was enough, making Donnie snap out of his trance and quickly shut off Raph’s machine so as to give him a few minutes to recover. As he did so a loud churr from next to him made him jump slightly, turning to see Leo following suit, his tube filling with cum as it erupted from Leo’s cock. Unlike Raph Leo’s back arched, a deep shuddering whimper slipping from his mouth along with a gasp of “M-m-Mikey!”

At the calling his brother’s name Donnie raised an eyebrow, chancing a glance at their littlest brother. Was there something between Leo and Mikey? But Leo was climaxing now, making Donnie turn and watch as their fearless leader reached his peak. Biting his lip Donnie watched noting how many loads Leo produced. 2, 3, 4; a truly impressive amount, each one seeming to be the same volume. Against his will a small thought popped up in his mind. He'd have to be sure to not let Raph or Leo see who’d cum more. Otherwise they'd end up fighting about that too.

Quickly he shut off Leo’s machine, allowing his oldest brother to pant and groan weakly as he to lie back on the bed. Only Mikey was left now….

Glancing at the monitor Donnie frowned as he found Mikey’s brain waves were much less intense than he'd expected them to be. If the readings were right he wasn't even close to cumming yet.  Frowning at the readings Donnie checked the connection to Mikey’s collar. With Leo and Raph recovering it was only Mikey who was grunting and churring now; his higher pitched sounds not nearly as distracting as the others were. Again Donnie frowned, finding that the connection to Mikey’s collar wasn't the cause of the low reading. Looking up to watch his brother Donnie moved, making his way to his youngest brother to be sure everything on the machine’s end was working correctly.

He worked as carefully as he could, doing his best to keep from touching his brother or risk throwing off the results of the test. But after several minutes of looking Donnie’s frown deepened. Everything was working properly. The machine was working correctly, there should be no reason why Mikey’s reading should be this low. Remaining silent Leo looked down at his brother. Mikey seemed to be lying, almost lazily in the bed. Unlike Leo and Raph who had pulled and tugged at their restraints Mikey was laying there almost motionless. The only movement Donnie could see was the rise and fall of his brother’s chest and the occasional clenching of Mikey’s fists. Biting his lip Donnie shifted his weight from one leg to another. He needed to make Mikey cum. If he didn't then the experiment would be incomplete. But…..

Slowly a thought began to creep into his mind. Out of his brothers Mikey had required the least convincing to agree to the experiment. And if he was being honest Mikey had always been the most promiscuous of them; seemingly always ready to fuck, even at a moment’s notice. Was it possible that Mikey’s interest in sex had caused him to develop a higher tolerance to pleasure?

That thought grew in his mind the longer he thought about it. Mikey had always been more sexually inclined than his older brothers. A few times Donnie had even gone into Mikey’s room only to find the youngest turtle in the middle of some sexual escapade or act. It would certainly make sense that his heightened interest in sex would lead to increased stamina. No doubt Mikey was enjoying this, the machine as its current pace not enough to make him climax as fast his other brothers. Sighing to himself Donnie weighed his options. He needed Mikey to cum soon. According to his schedule he needed to let Leo and Raph rest for 5 minutes between climaxes, so as not to hurt them; so he had a little time. But…..Mikey would need to cum…. And sooner rather than later if he wanted to keep his schedule.

Glancing at the clock Donnie made up his mind. Moving back to the desk he pulled open one of the drawers, pulling out a small device wrapped with a few wires around it. He'd brought the devise incase the milking machine had failed. But he'd never expected to use it. But now Mikey wasn't giving him a choice. Unwrapping the wires as he returned to his brother’s side Donnie gently licked the end of the electrode before leaning down and placing it at the base of Mikey’s tail. In the back of his mind Donnie could not help but wonder what it would feel like. Mikey had ALWAYS loved it when people touched his tail. Even as a kid, although that hadn't been for sex.

Flicking the switch on the side of the device, Donnie watched as the device began to charge for a moment. Beneath him Mikey groaned softly, seemingly oblivious to what was about to happen. For a moment Donnie looked down at his brother, noting how relaxed and almost peaceful Mikey looked. In a way he seemed to truly be enjoying what was being done to him. Sadly, what was happening wasn't for his enjoyment. It was about results.

Hitting the button Donnie triggered the device, making it dumps its electrical charge through the wire and into the base of Mikey’s tail. Of course the charge was low, not enough to cause any pain or damage, but enough to stimulate the already sensitive nerves. Almost instantly the tone of Mikey’s moans and churring changed, becoming higher pitched and more needful. Again Donnie pressed the button, sending another jolt of electricity through his brother’s body. This time Mikey grunted his back arching in response to the new stimulation. From inside the tube Donnie watched Mikey’s cock throbbed and pulsed in response to the shocks.

Mikey was starting to change now. The calm almost cocky attitude he'd displayed before was ebbing away. Donnie watched as his brother’s chest rose and fell faster now. His moans and grunts sounds more needful and lust filled. His hips moved now, trying to thrust upwards into the milker just as Leo and Raph had. Just one more……

Again Donnie pressed the button. This time Mikey’s whole body jerked, a loud gasping churr vibrating through his chest. A moment later Mikey’s back arched, a new sounds; a loud whimpering while echoing from his mouth. Inside the milker Donnie watched as Mikey’s cock twitched and throbbed, cum erupting from the tip before being collected by the suction of the machine. Just like with Leo and Raph Donnie kept count, noting how many loads Mikey produced. One, two, three, four, five, six; admittedly he was impressed. His youngest brother had produced more cum that the oldest brothers. Then again if his suspicions were correct, soon he'd be finding out all kinds of secrets about his youngest bro.

As the last of Mikey’s seed was sucked away Donnie moved, returning to his seat at his desk before pulling out the keyboard to the computer and typing in a few commands. A moment later the machine stopped, three loud hisses filling the room as the machine’s grip on his brother’s organs lessened before releasing them. Despite how recently and how much they'd cum Donnie noted that all three of his brothers remained fully erect and hard.

Jotting down his observations Donnie paused for a moment to look at his brother’s vitals. All three of them showed no signs of danger, their heart rates, blood pressure and EKGs well within expected limits.

Smiling to himself Donnie turned the page in his notebook, quickly scribbling at the top of the new page ‘PHASE 2’