Yeah, basically, guys just want to have the biggest dick because then there's..err..no excuse for his big ego.

I think we all know that NOTHING can shatter a man's ego than telling him that he has a small dick, whether or not it's actually true.

I think most guys feel that if they have a big dick and can prove it, then it can give him an excuse to be an asshole with a big ego. Nothing can really stop him, because he can't be touched in that area. Sure, calling him fat, stupid or ugly can be pretty insulting, but not as insulting as telling him that his dick isn't big.