Jennifer Aniston Gerard Butler W Magazine April 2010

Jennifer Aniston and her Bounty Hunter costar Gerard Butler steam up the April issue of W Magazine.

In the 13-page pictorial, Gerard plays a cop while Aniston poses as a sexy criminal in skimpy lingerie.

The spread - shot in mid-January on a ranch outside L.A. - is titled: "Speed Trap: Jennifer Aniston and Gerard Butler do a little role playing in the searing heat of the California desert where damsels aren't always in distress and lawmen sometimes break the rules."

Jen's hair stylist Chris McMillan says, "We left her hair dirty. It just created a nice chunky texture. The key to Jennifer's hair is no matter what you do with it - straight, frizzy, dirty - it looks like it actually grows out of her head. She's someone for whom her hair doesn't wear her, she wears it."

The Bounty Hunter co-stars, both 40, were shot by famed photographer Steven Klein, who happens to be a longtime pal of Jen and her ex-hubby Brad Pitt. Interestingly, Steven is the same one, who shot Brad Pitt and Angelina Jolie's famed "Domestic Bliss" pictorial for the mag back in 2005.

Jen and Gerard's upcoming movie The Bounty Hunter opens in theaters March 19.