...a horse. And a large looking stallion at that.
Tom smacked his lips, feeling a slight numbness in them that was soon spreading to his cheeks and chin.
"Are you okay?" Matt asked as he looked concernedly at his friend.
"Wh-why do you ask, man?" was Tom's slightly wobbly answer. The color had gone out his face and and hands as the blood had seemingly been sucked away. Matt's searching eye found the culprit as their was a pulsing bulge in the crotch of Tom's jeans.
"Tom, man, what the... what the hell?" Matt asked.
Tom then looked down and saw the massive swelling and was for a moment concerned. Then the bulge swelled and he felt odd. Undoing his belt, only further worrying Matt, Tom's felt some comfort when waist was able to sag out. In the space that had spread between skin and jean, Tom saw his swelling cock and more so the two orbs below that had already pushed out any human sperm, wetting his jeans, and started pumping equine hormones through his body.
Tom began to undo his belt, his mind addled.
"What are you doing? Stop, man. You're scaring me," Matt pleaded while Tom unzipped, his malformed cock, starting to grow into a sheath, snuck up his belly.
"Have have I ever mentioned," Tom started, letting his jeans fall to reveal a growing set of stallion tackle between his increasingly hairy thighs, "how much I wanna fuck a mare?" but as soon as he said it, Tom looked shocked that his did and grappled at his head. Thoughts of mounting and having free reign over the fillies were combating humanity and winning.