Rihanna wants to ''borrow'' Brooklyn Decker's boobs.

The singer and her co-star in 'Battleship' are both envious of different parts of the other's bodies, and would love to swap for a day to see what it would be like.

Brooklyn told Us Weekly magazine: ''We are envious of each other's bodies.

''We decided that I'm going to borrow her butt for a day - and she's going to borrow my breasts.''

Brooklyn, 25 - a former Sports Illustrated model - has also said she doesn't believe she is as good looking in real life as in photographs and she didn't enjoy seeing herself on the big screen in her new movie 'What To Expect When You're Expecting'.

She said: ''I have a glow, but it's good make-up. I cover up spots. Jeez, I'm not all that great in person.

''And seeing myself all blown up on-screen? Times a million enlarged? My face looks like it's been PhotoShopped. It's unnerving.''

Brooklyn has also recently revealed that she was, unusually, named after a horse.

She explained: ''I'm named after a horse. My mom's best friend had a horse named Brooke, so my dad suggested 'Brooklyn' as a more formal version, and it just stuck - and now I live in Brooklyn, New York, part-time, so go figure.''