In a new interview with Men's Fitness for their September 2015 cover, the handsome 32-year-old actor dishes on the many sex scenes he had to shoot for his breakout role on Showtime's The Tudors -- specifically, that one time he got an accidental erection.
"It's only happened to me once, and it was very embarrassing," he admits. "A girl had to be on top of me, she had spectacular breasts, and I hadn't rearranged my -- stuff into a harmless position. She's basically rubbing herself all over me and, um, it got a bit hard."
"I had to apologize profusely afterward," he adds. "It’s not great when you're in a professional acting environment and somebody gets a boner, is it? No, not acceptable."
He stresses that no matter how it ends up looking, the entire process is actually very "uncomfortable."
"You don’t think of sex scenes as showing your bum to the nation," he explains. "It's actually acutely uncomfortable being naked in a roomful of people. The very last thing it is is sexy. The actual physicality is very uncomfortable. All you're doing is smacking your nuts against someone, and nothing is going in."
"American dating is like carpet bombing," he says. "You date 16 women all at once and eventually one of them is supposed to pop out of the crowd? I can't do that. I'm 32 years old. I do want to find a wife and raise a family. I prefer the British way: get talking and see what happens, one at a time."
Though he wasn't always a hit with the ladies. In fact, he says he was overweight as a teenager.
"They used to call me Fat Cavill," he recalls. "I was a prime target for them. I actually had rolls of fat on me. One guy told me I had tits. I was a big eater, and I still love food. I'm still an indulger, in alcohol, in food, in all the things I enjoy in life. I've never been able to do things in half measures. That's probably why I was fat as a kid."
"And yet as much as people made fun of me, there was no actual bullying," he points out. " ... But I will admit I was quite bitter for a while. They also called me a 'lemon,' a guy who gets nowhere with the girls."
In June, ET caught up with Cavill and his co-star Armie Hammer on the set of their new film, The Man From U.N.C.L.E., which is based off of the '60s TV show. He dished that it was nice to be wearing a different kind of costume for a change.
"There were definitely difficulties with that particular costume [Superman], which I don't have with this costume,” he told ET. "It's just nice to be playing something different."