Jennifer Aniston: Jealous Of Nicole Kidman's '8-Pack' Abs

In her upcoming film, "Just Go With It," Jennifer Aniston plays the other woman, perhaps a frequent role in her career. But off screen, she's feeling the same way -- at least where celebrity bodies are concerned.

Aniston joined Ryan Seacrest on his radio show on Friday to talk her new flick and more -- including keeping in shape. While she admits to having a six pack -- "it's just sit ups!" she swears -- she's jealous of Nicole Kidman's extra pair of planks on the washboard.

Aniston got a full view of the mystical eight pack when Kidman was on set to make a surprise cameo in the film.

"I walked up to her and I said, 'I'm sorry, can I touch them? I have to touch them,'" Aniston Told Seacrest. "'Is that spray-painted? What is that?' I think it's an eight-pack."

Kidman showed Aniston her ways with yoga, but many might say the star of the film needs not be modest. Having turned 42 on Friday, a spread of her bikini photos may make the case for her. She also uses some tricks to keep up her metabolism -- check them out here.

To listen to the rest of the interview, click over to KIIS.com's Ryan Seacrest radio player.