John stared at Coach Ryerson in disbelief. The jockstrap that had been loose on Aaron was now skintight on Ryerson, leaving very little to the imagination as it displayed the outline of his 11 inch cock. Coach Ryerson grinned at John as he continued to stroke his shaft through the jockstrap; John found it difficult to tear his gaze away from Coach, feeling almost mesmerized by him.
"What...what the hell is going on?" John asked in a quivering voice.
"I'm assuming you swiped this from my gym bag?" Ryerson asked, gesturing towards the jockstrap he was wearing. John nodded in affirmation.
"I've had three of my jockstraps go missing in as many weeks from my office," Coach explained. "I knew that someone must have been stealing them, but they were impossible to catch. Luckily my husband is a bit of a wizard, and he offered to put a spell on my jockstrap. He promised that the next time it was stolen, I would be able to identify the culprit. I didn't realize that this was what he had in mind, but it's more creative of a punishment than I could've thought up," Ryerson laughed, glancing downwards and checking out his body.
"Did you say your husband is a wizard? That's impossible!" John exclaimed in denial.
"You just watched your boyfriend turn into your gym teacher, and you still find it hard to believe that magic is real?" Coach Ryerson asked flatly, rolling his eyes.
"It's not fair for you to punish Aaron; he was only doing what I asked!" John protested. "I was the one who actually stole it."
"Maybe you're right. I suppose you deserve to be punished, as well," Ryerson said with a wicked grin. Ryerson grabbed the rim of the jockstrap and slowly slid it downwards, exposing his erection and balls. He stepped out of the jock so he was now completely nude, holding the strap in his hand while he approached John.
"No!" John shouted, trying to run but finding himself unable to move. It was as if he was paralyzed in fear; John could only watch as Ryerson grabbed his boxer briefs and pulled them off of him, leaving him naked as well. "Why can't I move?"
"Must be a side effect of the spell," Ryerson answered. Coach knelt down in front of John with the jockstrap still in his grasp. After giving John's 7 inch boner a few strokes, he maneuvered the jockstrap up John's legs and over his crotch. John had a more athletic build than Aaron, so the jockstrap wasn't quite as loose as it had been on him, though it was a far cry from the skintight fit it had been on Coach.
"Please, Coach," John pleaded, afraid of what the jockstrap was going to do to him.
"Come on John, don't you want the body of a real man?" Coach Ryerson taunted, starting to jerk off his cock.
John could feel the jockstrap start to heat up, and soon a strange yet pleasing body flowed into his body from the jock. Despite his apprehension, John couldn't deny how good he felt. The power entering his body filled him with euphoria, and John felt like he was about to cream any second.
Ryerson watched on as the changes began, beating off his own dick all the while. John grew taller, going from a height of 5'7 to 6'1. His feet expanded as his legs bulked up, growing thicker with muscle while losing some of their definition. John's tight firm ass rounded out, adding a layer of fat. He moaned in pleasure as he felt his cock start to expand. His uncircumsised dick began circumsized as his foreskin vanished, his penis growing four inches longer and doubling in girth until it was the same size as Coach's package. John's balls dropped, swelling to the size of oranges as they quickly filled with semen.
John's chest began to swell with muscle and fat. He had had the lean defined frame of a runner, but that quickly disappeared as he packed on the pounds. His pecs inflated with muscle while his abs bulged outwards, leaving him with a bit of a gut. His shoulders broadened as his biceps thickened with definition, the veins in his arms bulging out. A thick treasure trail formed on John's chest as coarse dark brown hairs emerged from his skin. Similar hairs sprouted from his legs and arms, leaving the previously smooth teenager with a hairy bod.
The pleasure eradiating from John's cock continued to grow until John could not contain himself anymore. He let out a manly grunt as his cock started to spurt out cum, drenching the jockstrap he was wearing in semen. At the sight of his student cumming, Coach Ryerson let out an animalistic roar and began to ejaculate as well, drenching John's chest with his seed.
John's face began to mature as he started to take on the same facial features as Coach. He lost his round, boyish face as his jaw squared out and he grew some stubble on his chin. His bright blue eyes darkened to a mossy green while his styled, wavy black hair shortened into a crew cut and grew lighter, settling at a dark brown colour with some silver highlights throughout.
The Coach Ryerson that was in the nude looked at his former student, who was now an exact replica of himself. The new Coach Ryerson slid off his jockstrap so he was now naked as well, slowly running his hands along his rock hard shaft.
"Well, I think we taught those boys a lesson," He laughed.