Half-Sibling, All Fun

Groaning, Cassie tossed herself onto her bed, the hybrid’s sharp horn nearly skewering her pillow as the teen buried her face under her arms, moaning and squirming about, unable to find a comfortable pose, sweating even though she'd already stripped off everything but her underwear. The 19 year old girl had suffered through her fair share of heats in the past, but this one was more intense than any she'd gone through before, leaving her teetering on the edge of losing her mind and just turning into some wild beast. Flopping around onto her back, the teen splayed her legs wide open, trying to fan herself as she panted with her tongue hanging out, brushing away some of the long blonde hair falling onto her eyes. A mix between a Belgian shepherd and a unicorn, Cassie had a very unique look to her, a tall and slender form reminiscent of equines but with the canine brown coat of her father, sporting a pair of hooves, a fluffy tail, and a singular long, brilliant white horn, a gift from her mother. The girl's intriguing look had certainly gotten more than a few boys from her school interested, but Cassie had always focused more on her studies rather than chasing tail, something that the teen always came to thoroughly regret when it came time for her to struggle through another bout of estrus without the help of a male. Of course, just because she was alone didn't mean that the hybrid couldn't relieve some of the pressure her heat was causing, having already gotten herself off several times just that evening alone, her panties utterly drenched through, the soaked fabric sticking to her puffy pussy lips as she rolled around on her bed, groaning miserably. 

Cassie felt a burning temptation to stuff her fingers into her mound again, to rub at her clit and ride her own hand until she'd come to yet another shuddering climax and spray her bedsheets once more, but the young woman knew that all it would accomplish was maybe a minute of relief before the desperation would settle back in again, twice as horrible as it had been before. Masturbation would only offer brief, momentary relief from the hell of her estrus, what she needed was a real male there with her to take care of her heat once and for all, a luxury the teen unfortunately didn't have. Cassie could at least suffer through the heat in peace, with the rest of the family having left her home alone. Her parents had left on a business trip, and her siblings, both the half-siblings and her true brother, had gone away to sleep over at a friend's place for a few days. Writhing around in bed, biting her lip as one of her hands slowly trailed down her chest and belly to between her thighs, the hybrid huffed as she pushed her wet panties aside, her fingertips caressing her sensitive pussy lips, making her legs quiver gently. The horned and horny girl wished she had a boy there, any boy at all, that she could just jump and rut like a feral animal, biting down on her free hand with a whimper as she pushed her digits back into her slit, gasping as she began to finger herself in the vain hopes of finally getting some comfort from her heat. 

Nearly dozing off as he laid idly back on the sofa, nestled between his siblings and friends, Markus had to keep himself awake as his eyes glazed over, not particularly interested in the show that his half-brother had picked for them to watch. It didn't help that the entire living room was so stuffy, fluff and fur nuzzled against him on both sides, the warmth entrancing the half-snake boy, making it a struggle just to keep his eyes open. Running his fingers through his fur, a yawn causing his cobra-like hood to open up, Markus strained not to fall asleep, the muted purple patterns on his coat blending into the darkened room as he slumped back. He wasn't entirely sure why exactly him and all, or at least almost all, of his siblings were having a sleepover at a family friend's place, it wasn't exactly a common thing for the lot to do, and definitely seemed like more of an excuse to get out of their house for a few days. The boy was suspicious that it had something to do with his half sister, since Cassie apparently was going to accompany them all on their little trip, but decided to stay back home at the last second due to a very convenient case of flu. Though Markus definitely would've preferred being back home with his computer and games, the cub was even more bummed out about Cassie not being there with him, since he actually quite liked spending time with her. The fellow hybrid was only his half-sister, both sharing a Belgian shepherd dad with him being half cobra and the girl being half unicorn, and Cassie was also about five years older than him, but he had still gotten very close with her ever since the two families had joined together. Markus had a few guesses as to why the half-equine might've wanted to stay home alone for a few days, away from her siblings, but didn't know anything for certain.

Realising he definitely couldn't stay up for a moment longer without something to take his attention, the boy reached for his phone, opening it up only to see that he was almost out of battery. With a groan, the young teen hopped up off of the sofa, stretching slightly before walking off, 
“I'm gonna go charge my phone, no need to pause the show for me, you can just catch me up sometime later.”
The cub's siblings gave a nod as he headed out of the living room, just about to go upstairs into the guest room and grab his charger out of his bag when he remembered that he hadn't actually ever even packed it with him, stopping midway up the stairs and facepalming as he shook his head, muttering to himself,
“Oh, you idiot!”
The screw up wasn't a huge one however, with their home just down the block, a few minutes away even by foot, meaning all Markus had to do was to quickly hoof it back to the house and grab his charger, probably able to make it back before his sister had scarfed down the last bowl of popcorn even. And of course, while popping over to their home to get the charger, he'd also be able to say hello to his half-sister, feeling slightly bad for leaving Cassie out of the fun, even if it seemed like she wanted it to be that way. Deciding that there wasn't really any reason for him to announce his departure to the rest of the gang, he'd just be gone five minutes tops after all, Markus just quietly slipped out the front door without any of his siblings or his gracious host noticing, heading out into the street and jogging back towards his home. 

Even just from the outside, a few steps away from the front door of the house, Markus thought he caught an odd scent in the wind, the sort of scent he really wasn't accustomed to. Though just a whiff, the smell immediately took the young teen's mind back to a field trip at a farm he'd had some time ago, similarly wild and untamed as some of the smells he'd experienced there, though not anywhere near unpleasant like those barnyard aromas tended to be. Glancing around his neighbours’ yards with a raised eyebrow as he dug his keys out his pockets, trying to see if some feral animal was wandering around the street and causing the odd smell in the air, the hybrid eventually got the door open, instantly realising that the source of the scent wasn't outside the house, but inside. The air was thick with the overwhelming and strong scent of a very needy lady as Markus opened the door, causing him to cough as soon as he took the first huff, feeling lightheaded for a moment as the perfume overpowered his senses. The boy couldn't make heads or tails of the smell, just standing at the doorway with his nose twitching as he sniffed and huffed it, his mind fogging up more with every breath he took, even if he didn't exactly realise it. Getting a better whiff of the scent, it was even more animalistic than what he'd thought before, yet also unmistakably feminine, arousing and invigorating, making him blush and pant as he just stood there, taking it in. Markus hadn't ever encountered the scent of a woman in heat before, in fact the cub hadn't even gotten further than a smooch on the cheek, yet his body was still reacting to the pheromones in the air, his instincts trying to nudge and guide him along. Feeling his pants tightening up, the hybrid peeked down to see the pair rather obviously tented, a bulge big enough to nearly pop the button right off the pants as his knot slid out of his sheath. 

Realising he'd just been standing in the doorway, getting hard while sniffing the air like some kind of a freak, the young teen quickly slipped inside and closed the door behind him, a sheepish look on his face as he slowly and carefully walked deeper into the house, unaware of just how much the heat was affecting his judgement. From the stairs, just off to the side and in shadows like a wild beast prowling for prey, the entirely naked Cassie silently eyed up her half-brother as he staggered in, not spotting the needy girl as he sat down on the sofa, trying to stop his head from spinning. The canine/equine hybrid had gotten the scent of the male long before he'd stepped into her view, instantly thinking that her prayers had been answered, at least before she'd spotted that it was one of her siblings. That didn't stop Cassie's mind from straying very far into some impure territories as she stared at the younger boy from the distance, grimacing with desperation as she tried to hold herself back. She knew how utterly wrong, and risky, it would've been to use her own half-brother for relief, but that part of herself was fighting a losing battle with the much bigger part of herself that wanted nothing more than to jump on top of any male within eyesight, no matter that male's possible relation to her. Of course, this wasn't actually the first time that Cassie had had thoughts like this about Markus, even if not quite so debaucherous, with the girl having developed a slight crush towards the boy over the years. She'd tried to suppress and explain it away, thinking it was only natural for her to fancy such a handsome looking boy and that she wouldn't ever actually do anything about it, but now, all of the sudden, her previously buried feelings towards the cub were rushing back to the surface in force, urging her to do as her instincts commanded her to. 

Without saying a word, only her heavy breathing audible as she slowly approached, Cassie stepped down the stairs and began to walk towards her brother, his ears perking up as she was a few steps away. Turning to the older teen and jumping up from his seat, Markus stared at his half-sister, a mixture of awe and trepidation on his face as his eyes almost immediately drifted away from her lusty gaze, going down her body instead, momentarily stopping at the breasts she was cupping with one hand before focusing at her loins. The girl stood with her legs spread open, her other hand splaying her pussy lips open, letting Markus get a very good look at her gentle pink inner folds, several strands of her sticky honey drooling down from her lips, sticking to her inner thighs like a web as she stood there, panting and staring down at the boy. Barely even in control of his body anymore, Markus tried to say or do something, anything, but found his mind just going utterly blank in reply, unable to process what was happening as he gulped, shivering slightly as he stared at his older sibling's juicy pussy. While the cub was busy ogling her, Cassie did the same with the male in front of her, the ravenous hybrid’s eyes flitting down to the visibly throbbing bulge in his pants, licking her lips as she took another step closer to him. With neither teen still saying a word, Cassie grabbed her brother's hand and guided it down between her legs, moaning softly as she pressed his fingers against her soaked and warm pussy, letting him feel just how desperate she was to get rutted, a whimper escaping Markus’ maw as she did the same with him, groping his erection over his pants, stroking and rubbing at the bulge twitching under his clothes. In the blink of an eye, Cassie suddenly leapt against the boy, jumping against him and knocking him onto his back on the sofa, climbing on top of him as both panted and moaned. Quaking and whining, his tail wagging the whole time, Markus felt up his half-sister's body as she began to rip his clothes off of him, undressing him as fast as she could, shoving her snout against his chest and sniffing as she took in his masculine scent, grinding her drenched pussy against his legs the entire time, humping him like she was a feral bitch in heat. 

Before he could even think about it, Markus found himself stark naked, his knotted cock throbbing against his half-sister's belly as she leaned in to lick and nibble at his neck, snarling like a wild beast as her wet pussy lips pressed against his thighs, leaving damp spots on his fur. Sitting up, on top of the slightly smaller boy, pinning him down as she panted and huffed, Cassie glanced down at his red rocket, biting her lip with a moan as she caressed it with her hand, rubbing her slit against his knot as the cub let out a strained whine, gently bucking against her hand. Cassie could sense that her brother was very inexperienced, almost as desperate as she was but unsure about what exactly he was supposed to be doing. Deciding that she'd lend the younger teen a hand, really wet his appetite and get his sexual instincts going, wanting an assertive and confident male to breed her until she couldn't stand on her own two legs for at least a week, the girl suddenly got up. Stepping over to the side of the sofa, bending down over the armrest, she beckoned for the confused boy, a blush reddening his face as he staggered up, his cock pointing straight up as he waddled around his sister. Markus’ blush only deepened as he stepped behind the girl, her tail raising up as she presented herself to him, her soaking wet cunt staring him straight in the face as she bent over more, sticking her rear up at him, practically demanding he get to work. Though wholly inexperienced with pleasuring ladies, the boy felt a certain push as his body tried to guide him, unable to do much more besides just trusting his own instincts, falling to his knees behind Cassie as he grabbed onto her flank with both hands, sticking his snout under her tail. Not quite having expected her half-brother's muzzle in her loins, the older hybrid let out a tiny squeak as his tongue pushed into her pussy, instantly melting into a puddle of moans and gasps as she rubbed her rear up against the boy's maw, shoving back to stuff his tongue deeper as both practically purred. 

Getting his first taste of pussy, his eyes rolling back as he relished the flavour of his own half-sister's mound, Markus continued eating out the horned canine, her juices drooling down over his cock as he moaned against her slit, panting harder and harder until he felt like he was going to explode, desperate for something more than just a taste of her cunt. Pulling his tongue out Cassie and standing up, the boy pressed his tip right up to her pink entrance, grabbing handfuls of her fur as he held his breath, trembling before thrusting in as hard as he could. The girl screamed out as her brother thrust inside of her, his thick cock filling up her pussy in a way that her own fingers or any toy could never, throbbing and twitching as her walls squeezed down around it, squirting copious amounts of precum as he leaned over her, mounting the half-unicorn as she clawed at the sofa. Cassie's slit felt utterly divine, as if she'd been made just for Markus, the sensation of her soft folds clenching down around his shaft nearly knocking the wind out of his lungs as he bucked deeper and deeper into the needy girl, feeling the urge to bury his bone balls deep into her and never pull out. Drooling over the sofa cushions, squealing as the boy's thrusting shoved her face down into the couch, Cassie felt her brother laying down over her, his snout buried against the back of her neck, both pressing together as he bucked harder and harder, stretching out her slit until his knot finally slotted inside of her mound. Both siblings howled out in pleasure as the pair tied, a flood of pheromones and ancient instincts telling Markus to knock the girl up as she climaxed, clenching around his knot hard enough that he couldn't pull out even if he wanted to. Though that certainly wasn't what the younger teen was planning to do, still humping Cassie as he grunted, hugging her from behind as he released his seed deep into her pussy, not even remotely thinking of the possible repercussions it might have. As the first ropes of cum splashed against her cervix, her legs shaking and her tail wagging, Cassie finally felt the first bit of true relief ever since her heat had started, feeling utterly orgasmic as she whimpered with an exhausted smile on her face, shivering every time the thick canine length buried deep in her cunt gave another twitch. 

Laying on top of his half-sister, gasping for air as he idly kissed and licked her neck, Markus clung to the older girl like she was a plushie as he kept grinding against her, gently humping as his knot throbbed between her pussy lips. Slowly but surely, the lust fogging up his mind began clearing up, and the realisation of what he'd just done began to settle in, his blissful and dazed expression turning into a rather unsure grimace as he pushed himself up, glancing down to see cum drooling from his panting sister's slit. The boy wasn't the only one beginning to rethink his decisions, with Cassie groaning as she bit down on her fingers, trying not to moan too loudly as she felt her half-brother's knot tugging at her pussy lips, feeling his seed filling up her womb. Neither quite knew how exactly to proceed, stuck together for at least the next few minutes with Markus’ swollen knot lodged in the girl's mound, the pair both glancing at one another with an awkward look, Cassie's flushed face as bright red as a tomato as the boy gave her a sheepish smile, 
“Hey, I… I left my charger in my room… so I… uhh…”
The one-horned canine turned away from her brother with a sigh, burying her face under her hands as she shook her head, 
“Just… shut up and don't pull out…”