Dan peddles hard. He could feel the immense strength coming from his now powerful legs as they pumped up and down, up and down, tensing and releasing the large bloated muscles that filled his once baggy gym shorts.
"I've...got to get home. Got to change this!" He mumbled with hardly a hint of exhaustion to his voice. His newly enlarged glutes bulged outward, working with his powerful legs as he stood on the pedals to hammer each one down as hard as he could. Flex, release, flex, release...his mind began to wander thinking of how hot his silky smooth legs and butt felt; mesmerized how the large sensual muscles made his body ache in such a good way. Such a tiring but good way.
It was the sudden slapping he felt on his bike seat that jarred him from his sexual daydream. Looking down he could see that his fat dick had stretched what loose fabric was left of his shorts, and was slapping against the seat of his bicycle. Every time he pumped a pedal, it would bob and hit the seat; pump, slap, pump, smack.
"Oh..my god, got to...got to jerk it..." He turned to wards a local park and then veered in the direction of their public restroom.
Clumsily dropping his bike as he neared, he bolted into the restroom and found it empty. It smelled of dirt and urine, but his dick by now was almost calling his name and he didn't care. He had his shorts down and his floppy cock out in one hand before he even got into the stall...