The 31-year-old actress - who strips down to her underwear in new movie `House of Lies` - admitted she upped her exercise regime when she found out she would be stripping off, but said those who expect to see her fully nude can "dream on".

She said: "I want two round cupcakes, always. I kicked my buns and abs sets into high gear when I knew I`d have to be in my bra and underwear on `House of Lies`.

"But I don`t show my crack! All the Mr. Skins of the world are like, `Ooh, Kristen gets naked!` I`m like, `Dream on!`"

It would appear Kristen`s fiance, Dax Shepard, is also a fan of her "cupcake" rear, as she joked that the couple "nauseate" themselves with how "mushy" they can be.

She added in an interview with Women`s Health magazine: "We nauseate ourselves with how mushy we are."

Despite the `Forgetting Sarah Marshall` star`s romantic personality, she admitted she has a "potty mouth" when it comes to swearing.

She explained: "I have a potty mouth. I`m not afraid to drop an F-bomb. I can love organic tomatoes and swearing - the two aren`t mutually exclusive."
sections: Celebrities