06/15/2009 at 07:00 PM EDT
Fergie does not want to be known as just "the booty-shake girl," but the singer/dancer/actress isn't shy about showing off her substantially toned body.
Fergie (real name: Stacy Ferguson) opens up about her fitness habits – and her sizzling love life with hubby Josh Duhamel – in the upcoming issue of Allure
Asked if she "dresses up" for Duhamel, she tells the magazine, "Oh, girl, I've got a big chest of fun little numbers, ones that I would never wear in public."
She adds that their sex life hasn't cooled down at all since getting married
in January. "Nothing's changed in that department. I like to have fun with my costume onstage; why wouldn't I in the bedroom?"
As for her body, she did go through some changes recently. The star, who is known for her rock hard abs, says she put on 17 pounds to play the sexy role of Saraghina, an old-world prostitute, in Nine
, the musical adaptation of Fellini's film 8 1⁄2
The extra lumps, she says, started the paparazzi talking pregnancy. "If I don't do sit-ups, my stomach sticks out," she explains.
While it was fun "eating our brains out" with costar Penelope Cruz, Fergie, 34, confesses it wasn't as much fun taking it off. "It was a very gradual thing," she tells Allure
. "I didn't want to be told what to do, and I wasn't mentally ready to crack the whip."
But, before the debut of her new album, The E.N.D.
she stopped procrastinating and started using Duhamel's trainer several times a week. Still, she says, "I'm not afraid to show my flaws, and I'm not going to try to be perfect."
Flaws and all, she has one pretty ambitious goal for herself. "Basically to be the best in this business, which is show business".