Tyler's head was now almost hitting the ceiling of the shower, his large body having grown even more last night than it had two nights ago. The water from the shower head struck against his chest, dripping down the hills and valleys of his expanding pectoral muscles and rippling abs. His boyish face looked down at me with a half-embarrassed, half-excited smile.

"Hey, Joe," he said with a hint of amusement. He moved his right hand down his chest, gliding past his large, perky nipples and feeling the new, wonderful muscles that had appeared overnight. Everything about this situation nearly floored me, but what had to take the cake was my brother's amazing rod between his legs. Completely and totally erect, it was bigger than any porn star's, and when Tyler's hand made it down far enough and brushed against it, the thick, meaty head began to throb. Tyler shivered, with pleasure, I assumed.

"Uhhh, I really need to go downstairs," I said as I turned and started to step out of the bathroom, but I felt a large hand grasp my shoulders as I did so, spinning me back around. Looking straight into Tyler's eyes, I saw a mixture of confusion and lust, fear and desire running throughout his face.

"Joe," he said, his voice low but powerful, "...help me. Please!"

I knew immediately what he wanted help with, but I definitely felt uncomfortable doing it. Finally, though, I started to stutter, "O-Okay, Tyler, I'll tell you what to do... First, you want to grasp your... yourself tightly."

"Like this?" he asked, wrapping his fingers around his thick meat.

"Yes. Yes, that's exactly right." I took a deep breath before continuing. "Okay, now you should take that same hand and rub it back and forth along the length."

He started to stroke his cock as I suggested, and his eyes lit up. He picked up on it quickly (as most boys his age would), already seeming to be a natural. Within seconds, his eyes begin to roll back into his head; he seemed to be enjoying himself immensely.

"O-o-oh, Joe!" he cried out. "This is AMAZING!"

I nodded as he continued to go faster and faster. His massive muscles were tensing and flexing, even sometimes causing his entire body to twitch or shudder. He hadn't turned off the shower yet, and as the hot, steamy water continued to run down his smooth skin, I noticed a stream of precum slowly starting to ooze out of his slit. "At least he's close," I thought.

In actuality, he lasted another five minutes. Every thirty seconds or so he'd quickly yank his cock upwards, and I thought he would be about to cum, thankful that it was almost over-- but he kept going! Just as I was about to try to sneak away again, hoping he wouldn't notice, he finally slammed his butt and back against the wall of the shower (causing two tiles to crack in the process), thrusted out his crotch, and began spewing forth hot white ropes of cum that splattered against the shower curtain and the bathtub basin. There were six shots in total before he was all done. As much as I hadn't wanted to be forced to watch this the way I had been, I admitted it was one if the more impressive displays I had ever seen, and Tyler seemed to have one of the more impressive bodies of any human on Earth.

As he slouched down, his face still in an overly-contended afterglow, he finally looked back up at me, a satisfied grin on his face, saying...