Dustin quit staring, and was about to leave but then he realized - the boy didn't feel any tightness in his underwear because Ty's magic was keeping it stretchy! He wondered what the limit was... well, why not find out?
Focusing his gaze back on the boy, Dustin immediately saw movement in his groin as his already-large cock began to swell up again. Passing seven inches, his bulge was starting to truly stick out. It looked like a small bubble in the front of his shorts, but Dustin knew that would soon change.
As if on cue, the boy's balls caught up to his cock size, swelling from golf balls to the size of tennis balls! The boy groaned as his underwear filled even more, Ty's magic constantly adding fabric to the front so that instead of feeling tighter, the boy simply developed a bubble in the front of his underwear, like it was made for his endowment!
Good thing too - it was starting to look like all of his underwear would have to be custom. Dustin was pretty sure they didn't make underwear for kids with nine inch cocks. Though he realized by this point the boy was closing in on double digits. His bulge looked ridiculous, like the boy had stuffed two tennis balls and a cucumber down his shorts. Yet the boy wasn't crying in pain from his underwear - in fact just the opposite, the sensation of the fabric on his underwear moving as he grew was stimulating him.
As the boy crossed into footlong territory, Ty's magic actually went a step further and rearranged things inside the boy's underwear, pulling his cock down through one of the legs of his shorts and leaving his balls more room to grow (and boy did they need it) up above. Quickly the boy's nuts blew up again to the size of softballs. Dustin honestly wondered how no one had remarked on the boy with the growing bulge by this point.
In fact, Dustin realized that due to Ty's magic, the boy's cock was actually in danger of growing so long that it would grow right out of his shorts and be completely exposed. The thought made Dustin giggle, and he kept staring.
By now the boy's cock was nearing 15 inches, and it was still completely soft! It was so close to the edge of his shorts. In fact as Dustin watched... yep he could see part of the boy's cock head peeking out. And it was still growing longer. Not to be outdone, the boy's balls went through yet another growth spurt, swelling from the size of large apples to a size bordering melons. If Ty's magic hadn't added an incredibly large pouch to the underwear, it would have certainly ripped by now and taken his shorts with it.
As his cock passed 16 inches, it was now completely exposed to the cool mall air. Feeling this weird sensation but not knowing what it was, the boy finally put down his game and immediately noticed the two melons in his shorts, not to mention the long tube of meat that actually emerged from the end of his shorts. Rubbing his eyes, he determined he was not hallucinating. Quickly looking around, he jumped up and ran to the nearest restroom. Dustin just laughed and looked for a new victim.