Although the Black Eyed Peas frontwoman Fergie doesn't want to be the member only known for shaking her ass, she isn't shy about showing off her toned body whatsoever.

She does just that on the upcoming cover of Allure, where she discusses fitness habits, getting sexy for her husband Josh Duhamel, and piercings.

As far as spicing things up in the bedroom with her actor hubby, Fergie Ferg dresses up to keep things hot.

"I've got a big chest of fun little numbers, ones that I would never wear in public," she tells the mags. "I like to have fun with my costume onstage; why wouldn’t I in the bedroom?"

That rocking body probably keep Josh interested as well. But, recently, the rapper/singer packed on some pounds, 17 to be exact. The weight gain wasn't because she was getting lazy though. It was for the role of Saraghina, an old-world prostitute in "Nine," the musical adaptation of Fellini's film "8 ½."

Fergie said the pregnancy rumors came from that weight gain. "If I don't do sit-ups, my stomach sticks out," she explains.

To gain the weight, her and her co-star Penelope Cruz were "eating our brains out", feasting on "everything fried and full of fat and salty." While that can be fun, Ferg says that when it came time to get back in shape, it wasn't as fun as gaining it.

"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."

Fergie is now gearing up for the release of the Black Eyed Peas upcoming album, The E.N.D..

To read the full interview, pick up the July issue of Allure, which hits newsstands June 23.