Keira Knightley had no qualms about exposing her naked breasts in new movie The Edge Of Love, because she believes sex scenes are far more realistic if performed by naked actors.

The 23-year-old didn’t have any hesitation about appearing in the buff, insisting nudity has even become a habit of hers.

She tells People magazine: "I always bare my breasts. It's not like it's only in this film!"

So when Edge Of Love filmmaker John Maybury requested her to remove her bra, she was happy to oblige: "I said, 'All right then.'

"It was very simple. It was a sex scene and I never like them when they've got bras on."

Check out the whole host of other stars who have gotten naked on film.