John and Aaron had been dating for a little over a year. The men had met in their freshman year of college during football tryouts and had become fast friends. Over the following years, their friendship had gradually deepened and become something more, much to their surprise. Neither of them had ever been with a guy before but were unable to deny the chemistry between them, eventually giving into their desires after a late night gym session. Though neither of them were ashamed of their relationship, they had kept it a secret as they'd been afraid of how the rest of the team and their Coach would react.
The two would often linger in the locker room after football practice, waiting for the rest of the team to head out. When they were finally alone, they would press their muscled bodies against one another for a makeout session. They had mutually agreed to take things slow, both men inexperienced at gay sex and unsure of what position they would be. Lately, their hookup sessions had escalated to sucking and jerking eachother off.
One night, as their last teammate left the change room after practice, John approached Aaron with an unusual request.
"Would you mind wearing this?" John asked Aaron, unzipping his backpack and retrieving a pair of black boxers.
"Uh...yeah, I guess I could," Aaron replied, reaching out and taking the jockstrap from John's grasp, "Why?"
"Truth be told, I swiped it off of Coach Ryerson, and I kind of have a huge crush on the man," John admitted, blushing as he looked down at the floor in embarrassment. "I thought it would kind of be hot if you wore it and we roleplayed as if you were Coach or something. It sounds kind of stupid now that I've said it out loud."
"It doesn't sound stupid; I'm just surprised. I didn't know you were into roleplay," Aaron winked playfully. He slid down his football trousers and jock, revealing his hardening 6-inch cock. Aaron kicked off his cleats and slid the boxers up his legs and over his genitals. The boxers were a little baggy on him, loosely hanging around his waist.
"Damn, babe," John growled in arousal, tossing off Aaron's football jersey so he was wearing nothing but the ill-fitting boxers.
"I guess Coach and I aren't the same size," Aaron observed with a laugh, looking down at his toned, muscular body and the oversized boxers he was wearing.
"Just relax, you look good," John whispered, gently pushing Aaron up against the lockers and giving him a passionate kiss. John's jersey and trousers quickly came off, leaving him in a pair of tight white compression shorts.
The men continued to kiss and thrust up against each other, lost in the throes of lust. Aaron felt a sudden surge of power flow through him, originating from the boxers. His crotch started to tingle, the electric feeling quickly spreading out through his torso and limbs. He let out a small involuntary moan in pleasure from the sensation.
"You okay, baby?" John asked in concern, pulling back from their embrace; he could feel Aaron's body tensing up.
"Yeah, I'm feeling fucking fantastic," Aaron grinned, spinning John around and slamming him against the lockers. John was a little surprised at Aaron's sudden aggression; usually he was gentle and slow during their romantic encounters. John was almost sure that Aaron's shoulders were a bit broader than usual, though he assumed his eyes were playing tricks on him.
As Aaron continued to thrust up against John, he started to grow taller. Aaron had been a few inches shorter than John, but was now taller than his boyfriend by nearly half a foot. His already impressive quads legs began to bulk up and thicken with muscle, while his feet expanded from a size 9 to 11, thick dark hairs sprouting from his toes.
John had noticed the changes and was filled with panic, pushing Aaron away from him. He watched as his boyfriend continued to transform, feeling a mixture of fascination and horror.
"What's happening to you, babe?" John asked, his voice quivering.
"I don't know... but it feels so fucking good," Aaron moaned, his voice deepening as his adam's apple grew more prominent in his throat.
Aaron's pecs ballooned up with muscle while also gaining some fat, his previously tight pectorals now drooping slightly over his abs. Speaking of which, Aaron's washboard abs smoothed over as he packed on some additional weight around his midsection, bulging into a small round belly. Aaron’s shoulders broadened, his arms inflating with thick muscle, his tendons and ligaments developing. His toned biceps and triceps grew even larger. Thick dark brown hairs grew across Aaron's entire body; he went from smooth to hairy in a matter of seconds.
Aaron reached a hand down and stroked his cock through the boxers as it grew longer and nearly doubled in thickness. His balls dropped lower as they also expanded, filling with semen. His tight firm ass rounded out, plumping with fat and muscle.
Aaron's stylish light blonde hair shortened into a crew cut, darkening to salt and pepper. His jawline grew more pronounced, a well trimmed beard forming along his chin and lips. His facial features began to age rapidly, wrinkles appearing as Aaron went from his early 20s to mid 40s. John couldn't believe his eyes; his boyfriend had changed into a completely different person right in front of him. Standing in front of John in nothing other than tight boxers and sporting a rock hard cock was his football coach, Coach Ryerson.
John stared at Coach Ryerson in disbelief. The boxers that had been loose on Aaron were now skintight on Ryerson, showing the outline of his 11 inch cock. Coach Ryerson grinned at John as he continued to stroke his shaft through the boxers; 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, slowly backing away from his Coach. Ryerson was standing between him and the exit, making an escape difficult.
"I'm assuming you swiped this from my gym bag?" Ryerson asked, gesturing towards the boxers he was wearing. Reluctantly, John nodded in affirmation. "I've had three pairs of underwear go missing in the past month 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 boxers. 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 own body.
"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 agreed with a wicked grin.
Ryerson grabbed the rim of the boxers and slowly slid it downwards, exposing his hard dick and balls. He stepped out of the underwear so he was now completely nude, holding the boxers in his hand while he maliciously approached John. John's fantasy of having an intimate encounter with his Coach was coming true, John realized; it was just not exactly what he'd had in mind.
