Mr. Miller looked over at the door. He frowned, but decided to open it. He stepped out of the jock strap and held it in one of his bony hands as he went over and opened the door.
In walked Toby, the school's best wrestler. Six feet tall and 230 rock hard pounds of muscle, his body was powerful but still agile, and it had propelled him to numerous victories in the ring. He wore gym shorts and a tank top, and was sweaty after one of the brutal workouts that he forced his body to endure. Coach Johnson had given Toby quite a bit of one-on-one personal training, and the results had been spectacular. An 18-year old senior, he was able to write himself notes to get out of class whenever he felt like it, but he never, ever, skipped the gym.
Toby's lips curled into an amused sneer as he saw Mr. Miller's pale, emaciated body. The two men were the same height, but seeing them next to each other just highlighted their contrasts. Toby was youthful and had broad shoulders, thick muscles, and a hefty package. Mr. Miller was in his forties, narrow, skinny, and below-average in the cock and balls department. Toby brushed past, snickering. "Not sure what you're doing in here, Miller. Shouldn't a sad sack like you be somewhere else? This locker room is for men!"
All the taunts Mr. Miller had endured over the years came back to him. He watched in the mirror as Toby walked to his locker and started spinning the dial to enter the combination. Toby would be the first. Miller walked over to the door and locked it once more. Then he returned to the mirror, watching as Toby opened the locker and began pulling off his sweaty workout clothes, stripping down to his own jockstrap.
"You should think twice about being such an asshole, Toby," Mr. Miller growled, speaking to the wrestler's reflection in the mirror. Toby looked up from his locker, and walked up behind Miller.
"What was that?" Toby growled, his face twisting with anger.
Mr. Miller didn't answer. He just stared at their reflections and pulled up the jockstrap. He felt his cock and balls swell and change, as Rob and Tom entered his nuts, and as Jim became his dick. His height began to increase as well, inching upwards as his muscles began to swell. He let out a loud groan, his voice getting lower and deeper as he grew, a grin stretching across his face as he watched his body change, and Toby's reaction to that change! In the mirror he could watch his chest bloat outward, his pecs becoming thick and beefy. He could watch his arms swell as his shoulders widened, his delts, bis, tris, and forearms adding hard muscle. Abs popped out along his stomach, and his lats spread on the sides, as his back broadened into a brutally big mass of flesh. His legs expanded, his thighs becoming thick and powerful, while his calves swelled with muscle. Toby watched it all with open-mouthed fascination, his angry expression replaced by a look of confused awe.
Chuckling in his deep new voice, Mr. Miller slowly turned away from the mirror, and looked down at Toby. "What were you saying, asshole?" Miller growled.
Suddenly sensing danger, Toby bolted, rushing for the door. But a big arm shot out and slammed into him, shoving him up against the lockers, stopping his flight.
"Not so fast, asshole," Mr. Miller purred, amused malice running through his voice. "I'm not done with you yet..."
Toby's eyes widened further at that. He looked the now-hulking counselor up and down, taking in the six and a half foot tall frame, the 350 pounds of solid muscle, and of course the lewdly-jutting jockstrap pouch. That last bit, in particular, made Toby nervous. And although Mr. Miller was the much larger of the two, Toby was the star of the wrestling team, and that wasn't just because of his size.
Toby moved quickly, escaping from Miller's grasp, spinning away from the hulking brute and racing for the door. He reached it, turned the handle, but it would not open. Panicked, he fumbled with the deadbolt, trying to unlock it quickly enough to escape. But before he could, huge arms encircled him, lifting his body off the ground, their power crushing. A moment later Toby was dropped to the floor on the other side of the locker room, away from the door.
"Come on, boy," Miller taunted, "Don't tell me a boy snuck in here! This is for men!" As Toby stood up Miller sprang into action, grabbing the wrestler and pinning him to the floor. Toby was shocked. Being held down in that position was like all the times he practiced with Coach Johnson--the only person who could routinely best mighty Toby. But Toby didn't even remember those times, since Ty had wiped the coach and the trio of jocks from everyone's memories.
Mr. Miller chuckled as he manhandled the cocky senior. He didn't just have Coach Johnson's big body, he also had the man's skills! The counselor had never been much of an athlete, but he had gained the body and abilities of one. There was a certain irony there, and he relished it, as he overpowered one of the school's star jocks.
"I'm sorry!" Toby sputtered, realizing that he would not be able to muscle his way out of Miller's grasp, and would have to try talking his way out instead. "I'll never mock you again! I swear!"
"You sure won't, asshole," Miller replied, "I'm going to make sure of it."
Miller reached down, and pulled his cock out of the jockstrap. It was weird, having it look like a very muscular version of that stupid football player Jim, but as he ran his thumb across the little body, it felt just like it did when he touched his own dick. He pushed forward, rubbing it against one of Toby's muscled glutes. Before the young wrestler even realized what was happening, Miller thrust forward, ramming his Jim-cock into Toby's tight hole.
The arrogant senior gasped in shock as he felt the huge intrusion, and tried again to struggle and get free. But Miller was too big, too strong, and too skilled, and his cock was driven in way too deep. "You're mine now, boy," the huge man growled as he began to thrust, driving his muscledick deep into Toby, making sure the athlete felt all 12 inches of him. He looked up, grinning as he looked in the mirrors around the locker room. He could watch himself fuck Toby from multiple angles, and in all of them he looked amazing. But he wanted more.
With each thrust, he began to siphon some of Toby's size and strength. He watched himself grow in the mirror, chuckling as his body swelled even bigger. Toby writhed beneath him, trying to escape, not wanting to admit how good it felt to get pounded by the hulking counselor. But Miller wasn't going to stop until he was satisfied. He fucked Toby harder and harder, slamming his giant body against the teen's shrinking ass, feeling the boy get smaller and smaller while he himself grew. Finally, with a mighty bellow Mr. Miller came, shooting a huge load into Toby's exhausted ass, making the once-great wrestler moan from pleasure.
After every last drop was out of his dick, Mr. Miller slowly stood up, pulling out of Toby. The older man was 6'9" tall and 450 pounds. He smirked as he admired his body in the mirror, flexing his giant muscles, admiring what he had done.
Down on the floor, Toby was only 5'9" tall, a full foot shorter than what Miller had become. But that was nothing compared to the rest of Toby; his strong muscles were mostly gone, leaving him a scrawny, 130-pound weakling. As Toby looked over in a mirror to assess what had been stolen from him, he had a realization even more horrifying than the sight of his weak new body: that by the time Miller came in him, he was enjoying getting fucked!