Mark got comfortable and sat on the carpet in front of Ty. He felt amazingly helpless as he realized just how small he had become, and decided to do something about it. First, though, he was going to completely abuse Ty’s powers.
"Okay!" Mark said, grinning as he stood up on his hooves for the first time and wobbled slightly. Ty laughed at that, but listened patiently for Mark to continue. "I’d like to order you around a little. Can I still do that?" Ty nodded, and reached over and poked Mark’s chest with his finger, sending him off balance and causing him to fall onto his equine rump. Mark snorted and neighed playfully, and then got back to his hooves, smiling slyly. "Well!" he mock snarled, "if you’re going to insist on treating me as a plaything in this state, I’m just going to have to grow back up and teach you a lesson!" Ty nodded, but Mark wasn’t done yet. "First, though, how would you like to refill me?" Mark pointed to his small and empty testicles, and Ty grinned again.
Without saying a word, Ty concentrated on filling Mark’s balls back up to their previous state. The little horse whinnied in surprise and cupped both of his hands around each testicle, rather enjoying feeling them bulge and grow round and heavy again. Each swelled with the liquid inside, growing back to the size of two large oranges. Mark let go of them gently and felt them drop with weight. He walked around in a circle and couldn’t help but be amused at the wet slapping sound they made against his thighs. He’d need very supportive underwear from now on. If he even chose to wear clothing at all. He turned to face Ty again and his face lit up. He realized Ty had taken away his exhaustion and returned his body to its ready and refreshed state. It was like Mark had never had his tremendous orgasm at all.
So, standing there proudly and completely refreshed with his arms folded across his chest, Mark snorted and nodded affirmatively. "Make me big again, Ty. Please?" Ty got up off the couch and kneeled down in front of Mark. He put both hands around the little anthro horse’s waist, and let his thumbs rest between Mark’s legs. Mark looked a little surprised, "Er, Ty, what are you doing?" Without responding, Ty picked up Mark and let him dangle in his hands. Mark kicked his legs for a moment and heard his hooves clatter together a couple times. His gaze met Ty’s, and he felt a little uncomfortable at having the giant young boy stare at him like he was.
His body was suddenly engulfed in the same intense warmth that had been part of his transformation. He began to enlarge, but very slowly, gaining exactly an inch every several seconds. He would grow, then stop, and a couple seconds later sprout a little more. Mark smiled once again, and threw his snout into the air. He knew what Ty was intending to do, and with his pleasing enlargement he welcomed it now. His cock spilled out of his sheath and began to harden up again, and as he had expected, Ty’s thumbs began to massage it gently, moving up and down the length as it grew.
Slowly the little horse incrementally enlarged, gaining size rapidly but not constantly. Soon he was back up to two feet tall, and Ty stood him on the carpet so he could put his legs down. Amazing, Mark thought, he was now exactly as big as his penis was had he been full sized just then. Speaking of his penis, he looked down and found himself rock hard again. Ty’s thumbs massaged the big organ very gently, ensuring they touched his entire length evenly. He relaxed in Ty’s grasp and felt himself falling into blissful pleasure once again. Time passed like a dream, Mark growing, Ty providing him with stimulation. Soon, the tiny horse had grown to a much larger 3’ 0" and Ty let go of his waist and let him stand freely on the rug. He didn’t have to look so far up at Ty, who was sitting down in front of Mark, one hand jerking his horse rod now, but not hard enough. Mark rubbed his hands over Ty’s, urging him to go faster.
Their gazes met, and both grinned as Mark reached 3’ 6". What Ty did next was very surprising, but not entirely shocking. The young man leaned forward on all fours in front of Mark, and placed his mouth next to the enlarging animal’s warm meaty cock. Ty’s eyes looked up at Mark, now 4’ 2" The grinning snout looking down at Ty nodded wholeheartedly, and Ty took what he could of Mark’s plump throbbing horse member in his mouth. Ty slurped and sucked away, and Mark noticed his growth stopping. He was just 4’ 5" now, much bigger than he had been! That is, until the growth started to reverse. Ty was shrinking him again! "H-Hey!" Mark cried. Ty ignored him and continued feverishly sucking on him. Ty kneeled again and grabbed Mark’s shapely equine rump. Already down to 3’ 8" once again, Mark whimpered from both the stimulation of Ty pleasuring him, and his sudden unexpected shrinkage.
3’ nothing and he stopped shrinking. Frazzled and aroused, Mark gave in to Ty’s relentless oral sex. He felt himself building up, moaned in ecstasy, and began to quiver as another massive orgasm started to surface. Suddenly, sensing Mark’s imminent climax, Ty gently let his long little penis slip from his mouth, but not before licking up the precum that had started to drip from the tip. Mark ached with desire, but he tried to control himself. "D-Did I do something?" Mark asked, not entirely sure if he had displeased Ty, feeling submissive. "No," Ty said, licking his lips, "I just wanted to taste you at the size you’re at now. I’ll grow you again." Ty took a step back from three foot Mark, who stood in the middle of the living room holding his hardened and needful organ in his hands.
The intense fiery warmth that spread over his body the next minute was intoxicating. So much so Mark’s legs buckled, sending him head over hoof to the ground. He cried out in pure carnal lust as his penis suddenly burnt with the hottest pleasure that he had ever felt in his entire life. Ty grinned, taking a seat on the couch to watch Mark, stripping off his boxer shorts and becoming naked himself. Ty took his firmed erection in his hand and began jerking off.
Mark didn’t notice however. He didn’t care about his circumstances or what was happening to him. He was about to burst from the pleasure rampaging through his new body. He ached and convulsed on the carpet, and finally his two-foot cock exploded forth with a thick stream of come that arced into the air and splattered over his legs and the rug. He grew more muscular. Like an inflating balloon, every inch of muscle on Mark’s body hulked out and expanded tight and firm. His eyes rolled back into his head, and he neighed furiously as his spewing penis hardened further. Mark was drenched in his own fluids, and his furry body became soaked. He quickly built up a physique usually reserved for world class weight lifters. He was swollen incredibly with pure tremendous strength and muscle.
He cried out louder and thrashed around violently as spasm after spasm of orgasmic energy fueled his body’s changes. Having grown to his peak in muscle tone, he simply enlarged all together, shooting up to eight feet tall in a matter of seconds and then stopping. The power and force of his final growth caused him to pass out with a silly grin on his face that lasted for hours afterward.
When he woke up, it was the middle of the afternoon and Ty was sitting next to his relaxed and content body. Apparently, Ty had cleaned him and living room while he had rested, because there was no sign of his incredible release. He sat up, scratching his long equine ears, and then stretched. He looked himself over, and finally realized the true extent of his muscle inflation… and his height. He blinked, blinked again, and realized that when he had sat up, his ears brushed against the ceiling. He gasped, and realized he filled the entire living room. "T-Ty!" Mark said with shock, "just how big did you make me?"
"I made you into a 12 foot tall giant." Ty said with a grin, rubbing Mark’s tremendous sheath. Mark pushed Ty’s hand away from his genitals and looked down at him seriously. "This is too big!" He said. "Although," he smiled an extremely satisfied smile, "It was fun getting that way."