"No way these will ever fit me, but i wonder what it would feel like to wear them" Said Ryan to himself. He grabbed the humongous size 18 shoes and sat on the bench, catching a whiff of them as he swung them around.
"Holy crap!, these smell disgusting!" Ryan exclaimed, but for some reason, he felt compelled to smell the shoes again. Pressing the wet shoe to his face, he felt himself get hard. All of a sudden, he felt a tingling in his body, starting with his feet. The tingling became hotter and hotter, untul Ryan realised that it was actually his feet pressing against his shoes. He kept smelling the big sneaker, as his foot finally broke through his normal shoe, and kept growing, bigger and bigger, as he kept sniffing and licking the basketball shoe.
Finally, the growth stopped and he blew his load, and Ryan sat there in a confused daze as his memories were replaced. He was still the same 16 year old guy he was before, except he remembered that he was born with freakishly large feet, which kept growing through puberty and still increasing in size every year. He remembered that both his feet and humongous cock earned him the attention of many girls and guys in school, and that whoever smelled and sucked his big feet would also grow huge feet, though never as big as Ryans.
The new, improved Ryan walked out of the store with his new pair of basketball shoes, leaving his old, small size 9s for the next customer.