Shutting his eyes, Tom tried to think himself out of the situation as best he could. Still, even trying to measure his breaths, his torso was cracking and shifting, filling out more and gaining mass. When he let out a long breath, he could feel his face reshaping; tendons repositioning while bone starting to take on a new resemblance to a snout.
"It's fine, no worry," Kate said, passively trying to play it off. "My uncle's farm needs mares too. He's got a couple of stallions that'll make you happy you, uh," but she was cut off by the sudden disgusting sight of Tom emptying his new bowels, with horse turds rolling out under his lifted tail.
Head having been lowered, when he opened his eyes Tom was gifted the view of the growing pile of horse shit behind his hindlegs. When he went to move, the hooves clattered on the floor.
"It's not staAAAAAWping!" Tom bellowed, his voice warping as both his face pushed out and tongue grew to fit it.
"And it's not going to. Sorry again," Kate said, already turning away from both the sight and smell, to message her uncle to bring a trailer.
Gasping for breath, his glasses finally tumbled off his partially equine face, right along with the strands of brown hair from his head. All over his body, dappled brown fur and patterns were sprouting on his sweating pink flesh. At wait waist, following the growth of some teats, an udder starting to protrude, while Tom's sex finally finished it's transition and celebrated by going into a heat that raced through his entire body.
Holding to the wall still, he was only just above the ground with his hands when they cramped to the point of no return. He dropped to his now forming hooves and shivered as the sensation of being on falls hit him. His bones, muscle and mass quickly shift, and there was a feeling then of being on all fours for the rest of his life that struck Tom and caused his shaking to stop somewhat. The feeling radiating from his sex started to pervade his mind.
"W-why do I want to be mounted really bad?" Tom asked in a warped feminine voice that was husky and hard to make out at first. The two onlookers had no answer, "Oh fuck, it's really happening now," Tom muttered.
His arms tightened, straightened, and instead of looking, Tom shut his eyes and let his neck grow while his weight swelled to 1,000 pounds. Tom's neck grew thicker while mane and fur took the rest like most of his body. There was little left of Tom save some patches of flesh and a not fully formed snout. That was rapidly changing.
Looking back and spying his roommate, still trying to process his friend turning into a mare, Tom felt his sex pulse. He started to back up. "Fuck mreeee," Tom said in a guttural voice which only stood as Tom repeated it until he turned away to let his face grow those few more inches.
Matt was stunned to see the horse, now looming large, coming at him rear end first. That he could see his roommate was dripping, and now just a horse, made Matt's mind start to wander.
Tom would let the mare take over, instead made to watch as his body became nothing but animal, and a fertile one at that.
"So you gonna help him out or what, stud?" Kate asked, tapping her foot. "Gotta tell my uncle something so what's it gonna be?"