Steven had just stared eating the nachos that Tyler made, making sure to get some sour cream in between Kyle and James's aggressive dipping. Only after a few bites however, he felt a growing knot in his stomach and excused himself to the bathroom. As he made his way there the knot moved down to a pressure in his penis. He sped up his walking, thinking that he had to go really bad. When he arrived at the bathroom and pulled down his pants however, he saw that his cock had grown to almost twice it's size, and was now covered in small barbs.
Upon seeing his mutated dick, Steven found himself falling into a haze of lust as the mutation liquid began to fill his mind with lustful desires. Grabbing his now erect cock, Steven began to jerk himself off, completely unaware of the changes now spreading across his body.
Grey furs began to sprout on his arms, covering them from the elbows down. The same happened to his legs from the knees down. His furry feet them morphed into feline paws, and he was forced up on his toes as his legs became digitigrade. His ears moved up to the top of his head, becoming grey-furred and triangular. As this was happening, Steven continued to obliviously jerk off his cock, but just as he was about to reach climax, the door to the bathroom was slammed open by Jacob.
“Steven, Kyle and James are transforming, we think it mi...” Jacob's words trailed off as he saw the feline form of his friend.
With his climax interrupted, Steven looked over at his friend and was overcome with a raging desire to punish him for his disturbance. Jacob saw his friend's eyes become slitted as Steven gazed at him like a predator hunting it's prey. Before he could run away Jacob was grabbed by Steven, the mutants muscles growing larger as he forced Jacob over to the bedroom and roughly threw him down on the bed. Without giving Jacob a chance to get up, Steven pounced on top of him, pinning him to the bed while straddling his stomach. As Jacob was face to face with his friends throbbing cock, he caught movement as a tail, covered in the same grey fur as Steven's limbs and ears, grew out behind his friend. The tip of the tail was much thicker than the rest of it however, and the reason for that was revealed when it split open into a dripping vagina. Still lost in lust, Steven looked at his new appendage and grinned with a smile full of sharp teeth.
“I know the perfect tool to satisfy this...” growled Steven as he ripped off Jacobs pants with his now claw-like finger nails. With Jacobs cock exposed, Steven quickly enveloped it with his new vagina tipped tail, the infected juices causing it to grow hard.
As Steven milked his friend's cock, his body continued to change. His face became one of feminine beauty, with a pair of horns growing beside his ears. A pair of breasts stretched out his shirt, growing to a generous DD-cup, with his waist and hips shifting to give him a perfect hourglass figure. Jacob watched as his friend's body became that of a stacked, muscular, woman. Steven's already tight shirt was torn off when a pair of bat-like wings grew from his back, exposing his six pack abs and thumb-sized nipples.
As the mutations came to a conclusion, Steven found the orgasm he was previously denied building again. He ran his hand over his face and licked his palm with a rough, feline, tongue revelling in his, no HER new form. The manticore-girl decided as she came that feminine pronouns sounded much better in her head. With her new identity decided, she grabbed Jacobs head and shoved her barbed dick into his mouth just as she came from both her sexual organs, filling Jacob's mouth with her cum. The milking of his cock combined with having his mouth filled with cum caused Jacob to shoot his load as well, his seed travelling all the way down through the tail into Steven's womb.
With a mouth full of cum, it didn't take long for Jacob's transformation to start as well. His changes started with his penis shrinking down until it was pulled into his crotch and replaced with a vagina. His body was quickly transformed into that of a beautiful woman, with a thin waist, wide hips, a generous ass, and two cute B-cup breasts. His black hair pooled behind his prone form, growing long enough to touch the floor even when he was standing. His body also shrunk, going from 5'8'' to 4'11'' making him a full foot shorter than the manticore straddling him.
After watching her friend turn into a cute girl, Steven, no Steffany, she decided on the spot, leaned forwards and whispered into Jacob's ear, “Your changes have just started and your already such a cute girl.”
“No... I'm a man” Jacob weakly replied, the idea of being a woman already taking root in his mind.
“It'll be soooo much easier if you accept it. Most people who change sex when mutated end up changing gender identities within a year, I read that in the news once. So just accept it, I already have. I've decided to go by Steffany now, what should I call you?” Purred Steffany. Despite her aggressive posturing however, she was ready to back off if her friend put up more resistance. However, it seemed like her friend had come to terms with the situation when SHE said her name.
“Vicky”
As if triggered by her voice, Vicky's transformations sped up, green scales covering her arms and legs, as well as her hips and between her breasts. As this happened, Steffany flipped her friend over, and plunged her cock into Vicky's waiting, virgin, vagina. The transforming woman gripped the sheets with her hands, tearing holes in them as her hands became clawed. Webbing then grew down the outside of her arms, with four spiked “fingers” that could be used to fold them up against her forearms. Her feet grew into vicious looking talons, which she immediately used to grip Steffany's thighs. A long, tapered, tail grew from her behind, wrapping around her lover and pulling them deeper into herself, each one of Steffany's barbs rubbing against her sensitive folds. As Vicky came, small horns grew behind her head and her ears tapered off into points, completing her transformation into a wyvern-girl. Steffany wasn't far behind and shoot her load deep inside Vicky before the two mutants collapsed into the bed.
They were woken up a few minutes later when Taylor, the elf that had formerly been their friend Tyler, came to tell them that the apartment was being evacuated, but since the un-mutated people were going first they had a bit of time. Steffany pulled herself out of Vicky and the two of them went back to the living room where they saw the conjoined mutants that had formerly been Kyle and James, who now went by Kayla and Kelly, eating the now lukewarm nachos that had been abandoned after people started transforming. Vicky and Steffany, who had barely eaten any before, quickly sat down and joined them as the five women discussed their new bodies. Their discussion was interrupted by a flood of cum that began creeping under the door, as well as from the leak in the kitchen ceiling, but since everyone present was already transformed they didn't worry about it too much and continued waiting for the medical team to give them the ok to