A secret sex room? Feces-smeared couches? Another baby on the way? You can bet Kevin Federline and his lawyers are bound to take a keen interest in Star magazine's latest claims about his ex, Britney Spears.

The tabloid alleges that the plummeting pop star's Mulholland Drive mansion is equipped with a double-locked, X-rated "Fantasy Room" filled with ticklers, whips and fur-trimmed handcuffs hanging from the metal bedframe. (Please, hold your shudders until the end.)

The second-floor room also features a mirrored ceiling, a glass jar containing spanking paddles and a closet full of kinky outfits, according to an "insider" who stumbled into the den of sin.

"She wears Catholic schoolgirl uniforms, a maid's uniform and a Cinderella outfit," claims the mole. The source also contends Brit is so obsessed with Marilyn Monroe that she wants her nose redone to look like the blond model of self-destruction.

"Britney is sexually obsessed," the source tells Star.

Perhaps K-Fed knows that; they did make two babies. But his legal team, which scours the tabloid media for new evidence of maternal incompetence, is possibly less familiar with the claim that Brit leaves some of her sex toys out in the living room. When — and if — she regains custody of Sean Preston, 2, and Jayden James, 14 months, Federline may not be tickled about them finding her ticklers.

Star's source also claims the house is a stinky sty — that the white couches bear hideous stains of diaper-changing and Britney's dog. According to the tab, a "court-appointed watchdog" is set to declare the place a potential "health hazard."

But back to the pleasure equipment — who's helping Brit use it? According to the mag, her "new squeeze" is Michael Marchand, a Hollywood waiter and aspiring actor. But his mom insists that they're "just friends" who like "watching videos together and playing Scrabble."

Despite such innocent pursuits, Star quotes "multiple independent sources" as saying Brit is expecting again.

"Yes, I am pregnant and I am shocked — almost four weeks to be exact," says Brit, or someone claiming to be Brit, in a message on her MySpace page, according to Star. "I don't really know if I'm happy or sad I'm just ... idk [I don't know] I am happy I guess. I saw the ultrasound and it was really kewl!"

Spears' reps didn't get back to us. Federline's mouthpiece declined comment.

With Sean Evans and Shallon Lester. Edited by Lance D. Debler.