He told BANG Showbiz: "I don't know why but I like having it out. I like being naked! We all come into the world this way. There's very little you can do about it, you are who you are. Doing the scene, it doesn't matter. It's infinitely awkward. You have 40 strangers standing around.
"I think it's less awkward for guys than girls because the crew tends to be slightly more masculine. And, you know, mine doesn't look that much different from yours. Whenever I'm doing something like that, when it's a sexual scene I get out of myself by trying to make sure the other person's OK."
While the hunk – who is married to actress Demi Moore – is comfortable with nudity, he admits he wasn't so cool around girls when he was in High School.
He confessed: "I was a bit of a fumbler. Yeah, I didn't really have a girlfriend until I was a senior in High School. I was fairly nervous about the whole thing. I didn't manage very well."