Looking around again, Dustin spotted a boy sitting alone on the bench outside the store. The boy was playing a game on a cell phone, and his legs were wide open, allowing Dustin to easily see his cock and balls through his shorts. Dustin began to stare.
At first, nothing happened, then the boy's five inch cock began to reel out and grow longer. It uncoiled itself from the boy's underwear and began to grow, inching down the boy's leg. Dustin also made sure the boy's balls began to grow as well, slowly swelling up from their previous size as grapes.
As the boy's cock passed six inches long, it began to thicken as well. Dustin spotted movement on the boy's left leg, as the material began to stretch to cover the boy's bigger cock. It grew out still longer, and still thicker. By now, the boy's balls had become like small eggs. The boy groaned a bit from pleasure, but then shook it off, continuing to play his game. He took no notice of the slightly cramped sensation coming from his penis.
The boy's cock passed 8 inches. The excessive growth began to make the penis harden. As it struggled to pitch a tent, the shorts began to stretch out further. This allowed the boy's cock to have more freedom, standing straight up and tenting his shorts almost directly out. The boy's balls reached the size of large eggs, creating two more bulges just below his flagpole. The boy groaned again, louder this time as the pleasure from the head of his cock rubbing his shorts grew.
Dustin kept staring, enjoying the sight. The boy looked ridiculous by now, sporting a 10 inch dick with a rock hard erection. The shorts, previously stretchy, were at their limit, attempting to contain the gigantic tent it was creating. Below it sat two equally impressive balls, each the size of a large apple. The boy was groaning because the strain of the shorts was putting immense pleasure on his cock. He writhed in a combination of pain and absolutely euphoria.
The boy's balls tightened up. They shot a huge load through his cock. Combined with Dustin's still-active growth stare, the stress finally caused the boy's shorts to rip. The boy finally paused his game, put his phone down, and was met with a flagpole foot-long cock staring him in the face. Below that, two large apple-sized balls were visible. His jaw dropped and he ran into the men's bathroom to hide.