The weird thing is that in real life guys almost never talk about dick size. Unless they are just joking around. As a matter of fact I don't think I've EVER heard a guy in real life talk about his dick size unless he was joking.
I really haven't noticed it being every second question. I don't browse the sexual topics as much though, so maybe that's why. We have sooo many questions posted daily now, there's a lot about other things.