Heidi Pratt takes it all off -- almost -- in the September issue of Playboy. (See exclusive inside photos, left.)

"I did pose nude," the reality-TV vixen, 22, tells the new issue of Us Weekly, on stands today.

See more photos of stars posing in lingerie.

Although the racy photos that made it into the mag are PG-13 (she's wearing skimpy lingerie or a tiny bikini), she says she'll strip down completely after getting more plastic surgery.

"The body is a beautiful creation. If anything, the reason I didn't show everything is because I plan to get a few more upgrades," Heidi tells Spencer, who interviewed her for Playboy.

See Heidi and Spencer's cheesiest moments.

"I'm definitely not done with my surgical quest," she goes on, adding that she'd like "to go bigger on my boobs" for her husband, 26.

(Before going under the knife the first time, Heidi reveals she went "shopping for boobs" in the lad mag. "I wanted the best, so I sat down and flipped through a bunch of Playboys," she says. "The women are so hot -- Pamela Anderson, Carmen Electra, Marilyn Monroe, all the Playmates.")

See before and after photos of stars who have had plastic surgery.

Spencer says he hung up poster-sized photos of the nude outtakes on his bathroom wall.

"Now when I'm peeing, I get to see a 10-foot naked photo of of my wife," he says.

Heidi also admits she hasn't told her dad about her pictorial because she comes from such a strict Christian family.

"They're a little behind the times where he lives in Colorado, but he'll find out eventually," she says.