A corruptive virus is spreading through school. Cubs who are infected by the virus enter puberty and begin to develop sexually very fast. They experience extreme uncontrollable arousal and need to be satisfied over and over again. The mousetaur cubs are highly contagious and can infect others. A young bunny boy with black fur brings the virus home to his older brother. He is now infected and his puberty is out of control. He develops a massive sheath and a large set of testicles, bigger than his brother's. The bunny boy's older brother is taking a nap when the young bunny boy sneaks into his room. Seeing his big brother, the young bunny feels his butt start to grow and want to get fucked. The young bunny boy begins to feel a need to fuck and breed his older brother. The younger bunny climbs up onto the bed and gets in between the big rabbit's legs. His small furry hands pull his brother's shorts down exposing his soft sheath and balls. The smaller bunny begins to rub his brother's crotch with his furry hands. The big bunny opens his eyes and wakes up to find his younger brother between his legs. He looks down and sees that the smaller bunny has an erection as large as his arm. His little brother reaches up and pulls his pants down exposing his sheath and balls. The older bunny is shocked. He's never been attracted to other bunnies, let alone his little brother. But the way his younger brother looks and smells is intoxicating. His eyes roll back into his head and he loses control of his mind. He sits up and grabs his younger brother by the hips. The older bunny pushes his little brother onto his back and gets on top of him. He spreads the small bunny's legs and positions himself so that the tip of his sheath is touching the hole between the smaller bunny's legs. Then the larger bunny begins to push into the younger one, feeling that plump bunny butt growing larger and more plush. The big bunny begins to hump faster and harder, pushing more and more of his sheath into the younger bunny. His brother's butt is so tight and hot, and his tail is so fluffy and soft. Soon the large rabbit can't hold it any longer. His knot slips inside and his balls begin to swell. With a grunt the bunny begins to pump his cum into the smaller rabbit. The larger bunny's cock is so big and thick, the smaller one feels like his insides are being impregnated. The large bunny begins to cum again, this time harder. The smaller bunny squeals and whimpers in ecstasy, as the larger bunny pumps his cum into him. The big rabbit keeps cumming, filling his brother's ass full. The virus has infected them both. The older bunny's puberty is out of control. All the hormones are flooding his body. His balls are swelling, growing, and expanding. He feels the need to cum again, and breed his bunny fucktoy. He pulls out of the smaller bunny, and his knot slips out with a pop. His cock is still hard and he's still horny. He wants to fuck again. The larger bunny lifts the small bunny off the bed, and puts him on his lap. He can feel his smaller brother's belly growing into a plump gut, pregnant and fat. His cock slips back inside the tight hole, and he begins to fuck again. This time the large rabbit doesn't stop. His cock grows bigger and thicker, and he begins to breed the smaller bunny's ass over and over again. The bunny is losing his mind. All he can think about is fucking. He's addicted to the smell of his younger brother's scent, and the taste of his brother's cum. The bunny's balls are so heavy and full, they feel like they're about to burst. They're so big and heavy that the small bunny's belly has become bloated. He feels his ass grow even wider and rounder, and his tail starts to droop and sag. His ass is so full, he feels like he's going to explode. The big bunny keeps cumming, pumping more and more of his seed into his brother's ass. The smaller bunny can feel his insides being impregnated by the larger rabbit. His belly is a large, plump pregnant gut. The large bunny stops pumping his cum and his cock slips out of the smaller rabbit's ass. The small bunny falls to the floor, his legs too weak to stand. The larger bunny grabs the small bunny's waist and drags him to the edge of the bed. He notices his little brother's paws have grown very big with huge, thick toes. He takes the bunny's paw and sucks his fingers, licking the pads, tasting the sweet, fertile juices. The big bunny can feel his cock hardening again. His balls are swelling and growing, and he feels the need to breed his little brother even more. But the little bunny is too full and pregnant. The large bunny lifts the smaller bunny and puts him on his knees. He grabs the bunny's shoulders and spreads his legs wide, revealing his ass and mutated surprise. There are two buttholes! The larger bunny can't help himself. He thrusts his cock into the first hole. It's so tight, and it feels so good. He starts to thrust harder and harder. He's so close. He can feel the second hole stretching as his brother gives birth. The large rabbit grabs the little bunny's legs and pulls him closer. The little bunny's hole is so wet and tight, the big rabbit can't control himself. He cums so hard, he almost passes out. The birth is fast and painless. The new baby bunny has black fur and is growing rapidly. Its penis is as long and thick as its arm. Its balls are large and heavy. The little bunny's belly shrinks and the little baby is crawling all over its mother, licking its face, and trying to suckle. The large rabbit feels his balls grow and his cock swell. He can feel the urge to breed again. His balls are heavy and full. He lifts the little bunny and lays him on the bed, facing up. The larger rabbit spreads the bunny's legs and thrusts his cock into his ass. The little bunny's tail twitches and the little bunny cries out in pleasure. The big bunny is pumping his cum into the little bunny, impregnating him once more. The large rabbit is still pumping his cum into the little bunny when the smaller one gives birth again. It's another black bunny with a huge, throbbing erection. It crawls on top of its mother, licking his face and trying to suckle. The large rabbit can feel his balls grow even heavier. His cock swells, and his balls are filled to bursting. He feels his balls grow and expand, his cock getting bigger and thicker. The large rabbit is in heat, and he needs to fuck and breed.