As Ryan browsed the shoes, one pair caught his eye. It wasn't the design (they were fairly standard basketball shoes, just like any player would wear), but the size. Ryan checked the tag and his eyes bugged out. "Size 20?! Who wore these?". Chuckling to himself, he pulled the shoes off the rack and placed it next to his own shoe. It dwarfed his shoe, almost to the point where he could fit his shoe inside of this one.
"Guaranteed to fit, yeah right" Ryan snorted. Taking the shoes to a changing room, he pulled off his shoes and picked up the enormous shoes. Guiding his feet into the shoes and tying the laces, Ryan almost laughed. The shoes were comically large on his feet. He bent over to untie the laces when he shuddered and paused. His feet started to feel oddly warm inside. Ryan frantically pulled at the laces which would no longer budge. "What the fuck..." he mumbled just as he felt a transient surge of heat rush through him. His cock quickly hardened in his shorts, "... What's... happening..." he panted as gradually intensifying orgasmic waves rushed through him.
Ryan moaned as he felt his toes just beginning to slide forward in the too-large shoes as his feet started their expansion. His rock hard but modest five inch cock pulsed and oozed pre-cum with each heartbeat. The heat in his growing feet quickly began to fill his entire body. Ryan gasped as he saw his legs begin to lengthen, his feet stretching away from him... no he was growing taller! His legs also grew slightly thicker with muscle, but he noted that he lost some leg hair, though not enough to qualify him as female. He groaned as his spine pushed up, faster and faster, making him taller and taller. A light treasure trail began to grow up his stomach as it hardened into a slight six pack, and his pecs filled out as well, leaving him the torso of someone who was fairly athletic. His arms were next, lengthening outward. Ryan held his hands out in front of him as they followed suit, moaning and groaning as he helplessly watched his fingers growing longer and palms expanding; leaving him with slim, disproportionately large hands.
Next, his head began to warm up as as facial structure changed. Ryan could feel his head becoming more round, a younger shape. Facial hair almost completely disappeared off his skin, leaving him with almost a babyface. His feet were still slowly growing within his shoes, and his legs and spine were still lengthening! Suddenly Ryan groaned loudly and his cock began to expand slightly, growing only a couple inches more in length to 8 inches, but growing much thicker as well. It pulsed with the expansion, almost as if it had a mind of its own.
With a final burst of growth, Ryan's feet touched the end of the Size 20 sneakers. Slowly the orgasmic feeling dissipated and Ryan came to his senses.
His first thought was, wow those are long legs... wait, those are my legs!
Experimentally, he tried to get up. He almost stumbled on his new legs as he got up... and up... woahhhhh he was tall. Luckily there was a tape measure in the room. He measured quickly, and was astonished to see that he had grown over a foot to 7'2"! Turning to the side, he saw a mirror and saw himself.
He knew immediately on looking at his body that he was a basketball player, no doubt about it. While his Size 20 feet still looked huge, they no longer looked out of place on his body. His feet connected to much longer and stronger legs, complete with a strong torso and six pack abs that suggested he was an athlete. His arms were longer and especially his hands had grown, perfect for striking a basketball.
There was one area that didn't fit in however. His head had changed to look younger. Whereas before Ryan was 20, the man... or boy, as Ryan thought more appropriate looking at him, looked to be around 14 at the oldest. Ryan was dumbstruck - a boy could be this big? And yet the reflection mirrored his movements.