Ty spotted another boy in the aisles, looking at enhancing underwear. He must be shy down below, he thought. Oh no matter, Ty could help him with that! Ty wished that once the boy tried on the underwear, his cock and balls would continue to grow until he took it off.
The boy eventually selected the "MAX ENHANCE" model (how fitting, Ty thought) and headed to the change rooms, with Ty in tow. Ty really felt sorry for the boy at this point, he seemed like he was in need of a boost down below. Well, he would get one, he reminded himself.
Closing the door, the boy stripped down and Ty confirmed what he already knew. The boy had genitals on the small side, although not that small. Ty estimated around 2 inches soft, with grape-sized balls. Either way, he was about to do much better. Ty silently wished to be able to see through the garment in order to see better.
The boy slipped the underwear over his equipment and stared in the mirror. Instantly he jumped a bit as he felt a tingle, but relaxed, thinking it must be the fabric. Inside the underwear however, Ty could see the action: the boy's cock was starting to expand, lengthening and curling around in the underwear. However it still wasn't visible on the outside... yet.
The boy turned to the side to admire the view, and jutted out his hips slightly to accentuate the bulge. At the same moment, his expanding cock finally started to push against the fabric, pressing outwards just slightly. The boy's balls also began to expand, puffing up slightly as though they were being inflated slowly. The combination of these events produced a bulge in the underwear, which the boy smiled at.
Turning to another angle, the boy admired the bulge in his underwear. It looked average, maybe even a bit better than average, he shuddered at the thought. Ty however knew this wasn't the underwear. He could see that the boy now in fact did possess an average sized cock, running about 3.5 inches soft now and still growing.
The boy was now really smiling. He thought the underwear was taking in air, expanding to show off his bulge more and more. In fact, his cock was growing and pressing out the fabric more and more. Now up to 4 inches soft, the boy's cock was starting to rival most of his schoolmates his age. Ty could see space in his underwear was quickly becoming limited, and it was starting to show on the outside.
By this time the boy was proud. He was wondering what it was like to have a bulge like this all the time, not aware that that would shortly be his reality. Behind the underwear, the boy's now 5 inch soft cock was now above average, and it wanted space. The boy's balls had also reached the size of ping-pong balls, and were taking up more space as well. They now created a sizable bulge in the boy's underwear, but he still had no idea.
Bigger and bigger they slowly inflated. The boy was mesmerized by the results he was getting. He was lost in his imagination as he wished for a bulge like this all the time, showing through all of his clothes, never hideable. Meanwhile, his now-six inch soft cock was making that a reality. It was now pressing out the underwear so much that there was actually a faint cock outline showing through the pouch.
The boy moaned in pleasure as the fabric of the pouch rubbed against his cock as it continued to expand, pushing the underwear out and creating an extremely obvious penis outline. Amazingly, the pouch still covered the boy's cock, though it was swiftly running out of room.
Now lost in thought, the boy absentmindedly stuck his hand under the underwear and felt his cock. The sensitivity was enough to arouse him and his growing cock jerked and began to come alive, swelling up even more with blood as it came to full mast. And it was still growing!
Ty watched in amusement as the head of the boy's cock inched up through the material until it popped out of the waistband, head quivering as it continued to swell longer and longer. The boy looked down and his eyes bugged out with excitement. Quickly he removed the underwear, and the growth finally stopped.
Now exposed, Ty was able to see what had changed. Gone were the boy's smaller cock, in their place was a monster standing at full mast. Ty estimated a full 11 inches hard and as thick as a water bottle. Below that, the boy's balls hung, now the size of apples. Tentatively, the boy grasped his cock and began to pump it up and down, slowly at first but faster and faster. The sensitivity was enough to arouse him and his cock jerked and bucked, coming closer to a full ejaculation.
Suddenly, the boy came, in a thick rope of cum that splashed across the room. Ty was amazed how much there was! After a couple seconds, the boy finished and his cock started to go soft finally. The boy could not stop staring at his new cock. When it finally went soft, it was still at least 8 inches long and fairly thick.
Trembling with excitement, the boy pulled up his regular underwear and was overjoyed to see it strained to the limit, the fabric straining to contain his generous endowment. Pulling up his shorts did not conceal the enormous bulge either. The boy happily almost ran out of the room to go home, and Ty chuckled. Another happy customer.