When it comes to feeling embarrassed on screen, nudity's got nothing on singing for Keira Knightley. The actress, who gets naked for her new film The Edge of Love, told reporters, "I always bare my breasts! It's not like it's only in this film!" She goes on to explain the love scene between her and co-star Cillian Murphy. "It was very simple. It was a sex scene and I never like them when they've got bras on." However, when she realized she had to sing live in front of the cast and 100 extras, the actress suddenly got shy. "I thought I was going to die. My knees actually started buckling." Keira's mom, Sharman Macdonald wrote the film which stars her daughter. "I wasn't particularly pleased that Shar put singing into the script-in the first couple of takes I sounded like a pubescent boy," admits Keira.