Sean's head was still spinning from this morning. Everything seemed like a dream: one moment he was a 9-year-old boy reading comic books with superheroes in skin-tight spandex, and the next he became even bigger than Superman and Rob Liefield's version of Captain America combined. His muscles would bounce and flex at the slightest movement. And everything felt... really good for some reason.
Sean thought back to his first session in front of the mirror. Was it really his first time? His peepee looked gigantic; he could've sworn that they don't get much bigger than his father's when they used to bathe together. His face flushed again as the thought about his father. Sean began to feel hot as he felt heat coming from his groin. The monster inside his shorts formed a tent, and he felt a mix of discomfort and pleasure as it pushed around for freedom.
As if on cue, Eric broke him out of his daydream with a peck on the cheek. "Have a good day at school, OK stud?" Eric caressed Sean's face and leaned in for another kiss, but Sean quickly blocked it by raising his backpack between them. His biceps bulged and flared into an immense globe. Eric forgotten his failed attempt almost immediately as his eyes glued themselves to his son's impressive peaks.
"I-uh, don't want to be late, dad. See you after school!" Sean shuffled out of the car that barely contained him, his jerky movements causing the entire van to shake. Dressed in an XXL striped polo that strained to contain his torso and ripped cargo shorts that displayed his magnificent quads and calves, he waddled off towards the sound of the ringing bell. His dad took his time to admire him from behind for a few moments. His backpack and shirt did nothing to hide the wide expanse of Sean's back. His ass bounced and jiggled with each step.
Eric smiled warmly to himself. He had no idea that the gene for muscular hypertrophy ran in his family; it must've been a blessing with such a small chance of inheriting the traits to become a hulking behemoth. As he changed the gear into drive, his biceps bulged a bit more than usual. Eric brushed it off, and he thought about going to the gym more often just to keep up with his son's wild adventures every night. For such a muscular child, he certainly had the energy to match!
Sean glanced behind him, checking to see if his dad was gone yet, but then...