The underwear

Josh had always been curious how he stacked up against his dad. Josh was pretty well endowed but he'd not seen his dad naked in years, did the apple fall near the tree or was his impressive length something he inherited from his mom's family?

He slowly removed his trousers and his own underwear before pulling his Dad's worryingly stained y-fronts up his legs.

As he finished putting them on he felt a strange sensation in his crotch. The power was real and it was working! He crossed over to the mirror to get a better look, his eyes fixed on the bulge in his underwear as the changes came to a stop.