Tom tried to move but in his once more than ample common room there was little in the way of places to hide. He arms and shoulders felt tight, and pulled down and forward, forward his chest out and longer, thicker neck into a high position. Tom could see by the look in the mirror that his body was moving into the last stages as the fur migrated down his thickening arms and to his neck.
"Matt," Tom, voice wobbly, started, "are you going to fuck me?" The question was blunt but with hooves approaching from behind and his neck and small head not allowing him a view his swollen feel rear he felt he needed to know.
There was a bluster of air at Tom hide-quarters which caused his tail and ears to perk up. Glancing over to the mirror, Tom could make out most of the large figure behind him. Tom was about to protest when after another hot burst of air on his swollen sex, then felt a series of licks. Tom's tongue, a bit thicker, rolled from his mouth along with a squeaking moan.
Matt's face lifted up from behind Tom's mare ass, face pushed partially out in a muzzle with his hair having fallen out with a jet black mane coming in over his mostly pitch colored fur. "Bree-EIGHHHH-D!" Matt struggled to correct. His hooves tapped happily on the ground as he backed away.
Gathering himself, Tom picked up his head, only to see that now his nostrils were more equine and his jaw was numb. Turning his face to profile only showed that it was pushing out.
Before he could react, Tom's new hind legs nearly buckled as a sudden weight fell on it. He struggled to keep himself righted, all the while feeling something strong, powerful, and big shuffling and struggling somewhat on his back. It was when the prodding at his ass started that Tom was very aware of what was now happening.
"Mahhh-ttt," Tom managed, barely. He was unsure what to say as there was little he could and worse still- as his legs braced and sex relaxed and opened- Tom was starting to want it.
Matt had given in as the stallion's mind was not only too much, but too tempting as well. By the point he realized he was mounting his former roommate, he was just as happy to fuck himself away from here than live with the shame.
When the fat head of Matt's new cock finally found it's mark, it was a relief in some ways to both. Done thinking, Matt bucked and pushed in as hard as he could. Both watched their new head's grow in front of and after closing when the last of Matt's 40 inches drove home, they opened on what would be their permanent point of view. It didn't take long for their physical changes to finish and soon after, so did Matt. Tom whinnied as he felt a strange, warm sensation that was his first female orgasm.
Matt finally dropped off, leaving Tom's backside dripping with his spent seed. In their blissfully state, they didn't notice the walls bleed away or the barn come up around them but when Tom opened his eyes freshly, it was in a stable along with Matt, and he knew this was it.