I fucked a German guy a few years back who was the most incredible grower I have ever seen.
We were at a party at his place and he dragged me off into his bedroom and locked the door behind him. Well, he was a big bear of a guy with a bit of belly and all - not astoundingly buff in any way - and his dick, when we first fished it out, was just a thin short little thing. It wasn't tiny for a flaccid dick, probably average, but with his enormous frame it looked a little undersized.
When i worked him with my hands and lips he grew, naturally - and I starting thinking it was actually quite a fair size after all.
But I never known a guy just keep ON growing like him. All this dick seemed to be spontaneously generating in my hand - like some sort of gadget cock. It seemed like it grew some more after he started fucking me, and yet he was hard when he put it in. When he was fucking me it was just about taking my breath away - and when he pulled it out at the end and I got a look at it i couldn't believe how big he was - length and thickness.
It was one of the high points of my vacation, and something totally new to see such a "grower".