Matt stared as he watched Tom's balls shrivel away into nothing and get pulled back inside his body, his limp cock following soon after. Both got pulled into fatty and flabby pink southern lips that were now a porcine pussy. "You're... um... you're a sow, Tom." he finally managed to say, not believing his eyes.
"SqueeEEEEEEEE!" Tom cried, feeling the nice warmth that suddenly flooded into his loins. The sensation of his cock and balls retracting into him and forming a uterus proved only to turn him, or rather her, on more. "This feels soooo good!" she oinked as several rows of new fatty and squishy teats grew in on her underside.
Matt blushed furiously. He was actually kinda jealous of Tom. The sight of seeing Tom's belly swell up from under her ruined shirt and bust out of her old clothes turned the young man on so much. He wished he could join his now female roommate.
Tom shuddered in ecstasy as the warmth flowed all through her piggy body. Her torn clothes fell off her as she felt her hands and feet changing into piggy trotters. Soon her mind was being invaded by animalistic thoughts. Thoughts of getting mounted, and bred, and fucked into submission, bearing piglets for her to take care of so they could suckle milk from her round teats.
"Moooooroink!" Tom said in glee, struggling to speak. "M-Matt! You have got to join me! This feels so grrroik! Great!"
Sure enough, when Matt looked, there were plenty of pig vials, along with vials of many other animals. Matt was tempted, looking at Tom, to join his roommate.