Keira Knightley: 'I Don't Like Wearing Bras in Sex Scenes'

Keira Knightley says she doesn't like wearing bras in sex scenes.

The actress -- who stars in new movie The Edge Of Love with Sienna Miller, in which they both play two women who have a relationship with author Dylan Thomas -- said she insisted on taking off her bra for her sex scene in the film.

She reveals, "I always bare my breasts - not just in this film.

"I never like sex scenes when I've got a bra on, thank you very much."

Keira, 23, says she wasn't fazed about showing her breasts on the big screen, but was nervous about singing.

She adds, "That was terrifying. I wasn't particularly expecting to sing.

"I was like a pre-pubescent boy. My knees were shaking but a couple of shots of vodka and everything was OK."

Keira's role was written by her mother, Sharman Macdonald.

Keira added, "She dared to put a sex scene in it.

But said, "It didn't worry me that my mother knows what sex is.

"Come to think of it, I was found under an apple tree. My mother is a virgin. I had no hissy fits when she presented me with the scene."