As Jay watched, his feet stretched longer and longer, bigger and bigger, until they were nearly twice the size Ryan's had been, only considerably more slender and well-kept. He shivered all over and moaned as a tingle seeped up his calves, like stepping into deep, warm water. As his pants started to tighten, Jay rushed for the door of the shop and flipped its sign from "Open" to "Closed." His shirt tightened as he made a run for the center of the store, trying to stay out of view of onlookers.
Jay moaned again, louder this time, as the warm feeling redoubled up his legs. His muscles were spasming erratically, leaving him barely able to breathe, let alone stand. Pressure began to build quickly in his calves and thighs. Trying to get a hold of his body made Jay fall to the floor on his knees, immediately ripping the seat of his khakis. He floundered trying to lean back. The increasing tightness of his pants rubbed against his still-sensitive cock and made him impossibly hard.
He fumbled with the button on his pants until he managed to loose it, as which point the zipper beneath it broke as the sides of his pants were pulled apart by some unseen force. The waistband cut in to Jay's skin, deep enough that it felt like it was brushing against bone.
"Fuuuuck," he moaned as he looked down and saw two of the biggest legs to ever exist sprouting from his hips. They were almost as long as he used to be tall, and still growing, the exposed skin on his calves garnering a mild rugburn as it spread against the carpet. Jay only kept feeling harder and harder as his thighs, as thick as Ryan's but not as muscular, shredded the legs of his pants.
Jay was still average in terms of genitals, but that began to change as the growth in his legs tapered off. It just felt like his cock getting more and more aroused, on the very edge of orgasm, his balls bloated beneath it. Pointed straight in the air, it went from 6"... to 8"... to 10"... Jay was too lost in pleasure to keep track of his length, just knowing that it just kept going for several minutes. Propping himself up on his still-normal arms, the head of his erect penis reached several inches above his own head, and was nearly as thick around.
Heat pooled in his abdomen as his torso stretched out, becoming long and lean, ending in a smooth, bulging butt and that behemoth boner. Jay's legs clenched as his shoulders were pulled out, inch by excruciating inch, as his arms thickened and lengthened. His palms became sweaty as the warmth reached them, forcing his fingers to splay out as his palm cracked and widened. His fingers remained slender, but grew very, very long, ending with tapered points and smooth nails.
Jay didn't know what was happening to him, but the reaction was fairly straightforward: he was becoming exactly what Ryan had been thinking of when they fucked. In this case, however, Ryan had imagined both his dream partner and himself growing larger, with increasingly more cock. This gave Jay a smooth and slender body, much taller than Ryan's, and a cock close to 2' long.
His neck pushed up and lights flashed behind Jay's eyes as his head expanded to match the rest of him. The warmth started to fade, but Jay coaxed a few more inches here and there by denying his orgasm. He was at his breaking point when his cock gently rubbed against his chest, stimulating him until he came messy ropes of cum that covered the nearby wall and hit the ceiling. Jay rode his orgasm like the world's most intense rollercoaster, breathing hard when it ended.
Jay sat up fully to take stock of his situation. He was more than twice his original height with a cock that looked at least 18" long, soft. His legs made up most of his height, long and surprisingly curvy. Looking at his new plump thighs made Jay feel incredibly sexy. His shoulders, sitting down, were taller than some of the 5' merchandise racks around him.
Jay reached up to stretch and found that, even seated on an ass much more cushioning than before, he could touch the ceiling with no problem.
Cripes, he thought, that must make me almost 20 feet tall.
The shop around him looked amusingly miniscule, and Jay wanted to play with these life-like toys, but a sudden feeling of calm and swept through his body. He found himself laying back, head near the check-out counter, stretching his long torso. He yawned and folded a hand the size of a small table under his headband. The 23-year-old now-giant was going to nap, and then...