Megan Fox and Amanda Seyfried getting into a fight in their underwear in Jason Reitman's next producing effort, the horror-comedy "Jennifer's Body" says ShockTillYouDrop.

Reitman confirmed on Howard Stern yesterday that Fox ("Transformers") will be appearing topless in a scene in which she has lured a guy into the woods with her. She'll be wearing a skirt and apparently her hair will cover some parts.

Penned by Diablo Cody ("Juno"), the Karyn Kusama-directed film has a gorgeous cheerleader (Fox) possessed by a demon and she starts feeding off the boys in a small Minnesota farming town.