I actually heard a while ago that on average gay men have more sex than straight men, and the result was that it worked the penis out more -- which made the penis bigger. The argument was that the penis is like a muscle; the more you exercise it, the bigger it gets. I never know what to make of this story. I've been beating off since I was 12 or so, which is a workout, and my penis has remained average. So, who knows.