Keira Knightley talks nude scenes: I don’t mind exposing my breasts!

Keira Knightley doesn't mind showing some skin — whether it's for a scene in one of her movies or the cover of a magazine.

The British actress goes topless on the December cover of Allure. Wearing Tom Ford tuxedo pants, which are unbuttoned, and a black sequined Chanel jacket, the 27-year-old appears as confident as ever as she strikes a pose for famed shutterbug Mario Testino. However, she says she has her limits when it comes to nudity.

More Photos from Keira Knightley's Allure Cover Shoot

"Sex scenes in films — I'm quite rigorous about what gets exposed," the "Anna Karenina" star tells the magazine. "No bottom half! I don't mind exposing my t-ts because they're so small — people really aren't that interested." As for deciding how much she should show, "I think it's much easier as you get older. You can say, 'No.' 'Yes.' 'No.'"

Keira Knightley's Style Over the Years

Because Knightley doesn't have the chest of, say, Heidi Montag, the folks marketing her movies often get creative with Photoshop, which she isn't always thrilled about. "They always pencil in my boobs. I was only angry when they were really droopy," she playfully complains. "For 'King Arthur,' for a poster, they gave me these really strange droopy tits. …I thought, well if you're going to make me fantasy breasts, at least make perky breasts."

In the early part of her career, back in the "Pirates of the Caribbean" days, Knightley was plagued with rumors that she was suffering from the eating disorder anorexia, which she denied time and again — and continues to do so. "The anorexic stuff — all of that — it's always going to have an impact, so I think it did hit pretty hard," she tells Allure. Because you go, 'Oh, maybe that's right!' I knew I wasn't anorexic, but maybe my body is somehow not right. Or my face is not right, or the way I speak is not right. When you're going through a period where you're really getting a lot of criticism, you go, 'Maybe all this is right!' You just kind of want to hide it all."

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Engaged to musician James Righton since last May, Knightley tells the magazine she's not sure exactly when — or if! — they'll walk down the aisle. "Maybe I'll be permanently engaged," she says. As for what makes their relationship work? Being different. "We're total opposites," she notes. While music is Righton's life — he's the keyboardist for the Klaxons — she says, "I know nothing about it."

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And when it comes to going topless on magazine covers, Righton leaves that to Knightley.

For more of Knightley's interview, pick up the December issue of Allure, on newsstands November 20.

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