She gets naked on camera.
It's a first for the 41-year-old actress, who described the experience to Esquire magazine as "just a part of the role."
She says her co-star Jason Segel also gets nude on-screen.
In "Sex Tape," Diaz and Segal play a bored married couple who decide to spice up things by filming a sex tape. After it's accidentally leaked, they try to get it back.
She also has a labor scene in the film. Diaz has been open about not wanting children in real life, saying she never really wanted to be a mother.
(AP)