"You’re damn right I want you to transform me!" Mark cried. Ty grinned and went to pick up Mark in his hands, but the little man was not keen on that idea. It took some coaxing, but Ty convinced Mark to sit on his right thigh, on top of his hand for support, which was palm-up. Mark did so, and got cozy. So cozy that he didn’t at all mind when Ty reached down and took away his oversized shirt. Maybe Ty had willed him to allow himself to be nude. In any case, he was completely naked and sitting in his foster son’s hand with his legs dangling over either side of Ty’s thigh. "So… how do we… do this?" Mark asked. "Just relax," Ty said, "I’ll take care of everything. Maybe give you a nice surprise too." Mark smiled and entrusted himself to Ty, leaning back and awaiting his change. How exciting this was! He could become his most beloved animal!
Mark’s penis began to warm immensely and he unthinkingly wrapped his left hand around the limp shaft. To his amazement, the base of his shaft began to change color, darkening from a reddish pink to a deep jet black. The shaft changed color all the way to the tip, which began to reshape. Mark gasped as the subtle pleasure of having the head of his organ turn equine tingled through his body. The head became flatter, less bulb like, and his slit relocated downward. Mark was becoming aroused, and he didn’t at all mind letting himself give in to the pleasure.
Still sitting on the giant sized Ty’s thigh, Mark began to masturbate slowly. He was rewarded with his new horse member starting to stir and grow in his hand, sending hot tingling pleasure through his body, all the way from his toes to his head. His testicles were feeling increasingly warm just like his penis, and he glanced down to find they were growing in size. Gasping, Mark cupped his free hand around his balls. They too, began to darken in color to black, and they grew tight and round until just one was almost too big for Mark to hold in his hand. He sloshed both testicles around in his hand and found them to be completely full, not saggy and wrinkled like they were moments ago. He grinned at their size and wondered how much he could release now.
His penis was beginning to harden from his own steady stimulation. He looked from his testicles to his rod, and found the beautiful equine organ starting to stiffen and engorge in his hand. Like his testicles, it slowly started to grow larger, and Mark’s modest five inch length soon stretched and erected into a nicely thickened 8 inches. The long black horse member continued to grow, slowly reaching and then exceeding fourteen inches in length. By that time Mark had become insatiably horny and adding to his arousal was the warmth slowly spreading over his entire body. His full transformation was welling up inside of him, and it would only be a matter of time before he began to change all the way into a horse.
His eyes never left his penis, which had reached a spectacular eighteen inches long and three inches thick at the base. Mark’s need for pleasure increased with his organ, and he found himself masturbating wildly with both hands, jerking his rod as fast as he could. The hair on his hands began to thicken and spread up to his elbows. He masturbated faster, which prompted his penis to increase in size more quickly. The hair spreading up his elbows reached his shoulders and began to grow long and soft over his chest and back. His cock finally began to slow its enlargement and had grown impossibly huge at two feet long and three inches thick. Mark’s hair color turned a light brown all over his person as it spread down to his abdomen and began to tingle up the back of his neck.
With his massive horse endowment begging for a release and the feeling of his body starting to turn into a horse, Mark was the most aroused he had ever been in his life. With both hands still firmly masturbating his member, he pressed the red hot length against his abdomen and chest, gently extended his own tongue, and began to lick at the tip of his cock. It felt tingly and wonderful. Mark smiled proudly as his penis swelled only a tiny bit larger and began to drip tasty precum, which he angled onto his tongue and began to lap eagerly. By this time, his entire torso was covered in thick horsehair, and his facial features had begun to change. Even as Mark licked at his needful fully engorged horse cock, his transformation was changing him further.
He felt the warming sensation in his body peak and suddenly Mark's muscles were growing, stretching his skin tight over his rippling new muscle. His nose slowly seemed to melt into his face, reducing to two nasal openings above his lips. When this happened, his face began to press out from his skull, gaining length and definition. Mark’s sense of smell heightened and he smelt his own arousal so deeply that it pushed him closer to an orgasm. He groaned in absolute bliss, and without thinking he found himself setting his new lengthening muzzle’s mouth over his penis. With his enlarging mouth it was easy to take in as much as his own length as he could, and Mark began sucking on his own penis. The thrill of being able to merely perform the act on his own rod pushed him over the edge and a thick burst of salty juices sprayed from his tip down his throat, nearly gagging him. Mark doubled his efforts and suckled harder, bringing his penis to tremendous multiple climaxes that he had never felt before. Pleasure rippled through his body as jet after steamy jet of thick delicious cum poured from mark’s penis. The pleasure never subsided and showed no signs of stopping as he gulped his own reproductive fluids down.
In response to his pounding orgasm, the speed of his change doubled. His snout creaked and shot out longer, completing itself into a perfect equine muzzle. His face grew the same light brown horsehair, and his eyes darkened to a soft deep brown. Likewise, his ears stretched and grew pointed. They raised up on his skull. He came still, threatening to faint from the intense waves of pleasure coursing through his body. The hair spread quickly down his thighs and reached his knees in no time. Still sucking on himself, nearly exhausted of everything he had, he rubbed his rear into Ty’s hand as a tiny bump of flesh formed above his rump and then rapidly grew long and hairy. He now had a tail! He thrashed it wildly in response and its beautiful black hair fluttered about. Ty giggled, but Mark was completely lost in his moment and paid it no mind.
Mark finally let go of his cock and cried out a neigh of triumph as the last drops of his juices trickled out and his orgasm began to subside. He panted and realized his transformation was nearly through, as he saw his shaggy body hair reach his ankles, which reshaped oddly as his heels rose and his feet grew longer. His toes began to shrink away quite rapidly, all except for the middle toe on each foot, which instead began to grow. The nail on the enlarging toe grew hard and black, and expanded in size until it replaced each lost foot with a perfect horse hoof! Mark shuddered as his orgasm completed, and the warmth in his body gradually subsided. A large moist equestrian tongue hung to the side of his lips, and he panted wildly. His body was dripping with sweat. He inhaled deeply and loved his new rugged animal scent, and a smile crossed his lips.
Oddly, however, his change had stopped entirely. He was halfway between a man and a horse, possessing characteristics of both in a perfect blend. He was anthro! Mark’s grin spread wider, but he couldn’t help but feel slightly disappointed he hadn’t gone all the way. Quizzically, he looked up with his silly horse grin at Ty, who was smiling down at Mark. The big foster son gently picked up Mark’s tender shrunken body in both hands, and allowed him to lay down and relax as he cradled the little horse man with his legs dangling over the edge of Ty’s hand. Even having come to the point where his testicles had emptied so completely they had shrunk a little smaller, Mark still had a rock solid erection he guessed would take some time to drain back down. The young Ty was completely astonished, and excited. Holding the tiny equimorph in his hands, he reached over with one trembling finger and gently rubbed Mark’s big little penis from tip to base several times, making the foot tall animal squeal with exhausted pleasure as another instant orgasm trembled through his body. Although this time he had nothing left to ejaculate. A single trickle of juice fell from the tip of his cock.
Mark loved it as he thrashed in prolonged climax in the palm of Ty’s hand. There was something very sexy about being at the whim of somebody larger, completely at his or her mercy. He realized with sudden shame that was exactly the way he treated Ty. He got off on controlling his foster son’s life. And here, Ty had developed an incredible power somehow in the last 24 hours, and had given Mark this beautiful present instead of punishing him. As this thought ran through his mind, he felt Ty’s giant finger again stroke his penis. This time, however, he only came a little bit. A tiny shock of orgasm rather than the whole thing. His body had quite simply had enough pleasure. Mark’s penis began to feel heavy and he looked down to see his massive organ lazily receding and shrinking into his brand new genital sheath.
Mark looked up at Ty, his eyes feeling heavy as unavoidable sleep began to set in. “Ty,” he said softly, his voice now much deeper than it had been, “thank you so much for this. I promise I’ll make it up to you.” Ty grinned, gently rocking the little 12” tall creature to sleep in his hands. “I know you will, Mark. This changes everything between us. You have a sleep, now. I’ll take good care of you.” Mark nodded and shut his eyes. His body soon relaxed in Ty’s grasp, and then went completely limp. Mark had passed out from the experience.
Ty smiled warmly to himself, replaying the entire scene in his mind and feeling an incredible excitement build inside of him. It was so exciting, watching Mark go through his transformation so intimately. He slowly set Mark down on the seat of the couch, propping up his body against the armrest, and tucked him into his own oversized T-shirt so that only his adorable little horsey muzzle stuck out from its folds. Mark’s ears twitched and he snorted, and shifted to his side, now breathing peacefully.
Ty walked back to the kitchen and took a good look at the frozen Dustin and June. What other fun could he have?