Don't ask me how I come up with this stuff, but one of my more odd fantasy daydreams is being in a threesome, with the woman seeing my dick for the first time and laying it on really thick about how big & fat I am and how she's looking forward to how it must feel....only to have her man drop 'em and turn out to be packing something that makes me pale in comparison and it turns out they set up the whole thing as a gag (but the threesome goes on all the same, mind you ).

I think the origin of that is a friend of mine years ago telling everybody how huge her BF was, and me ending up being the next guy she played with. Even though she measured me herself, and had earlier admitted average was only "5 1/2, 6" she never would come out and call me big.