Cameron Diaz Talks Racy 'Sex Tape'.....

Cameron Diaz Talks Racy Sex Tape Scenes with Jason Segel: 'We Had Each Other's Backs'

By Aili Nahas

Jason Segel and Cameron Diaz in Sex Tape

It's not every day that Cameron Diaz strips down in front of a group of people, but during the shooting for her new film, Sex Tape, she got very comfortable, very quickly.

"The whole movie is lovemaking between the characters," Diaz tells PEOPLE. "The crew was awesome and so respectful. It's not a vanity thing. It's about telling a story."

In the film, out July 25, Diaz and costar Jason Segel play a married couple who film themselves trying out every position in The Joy of Sex, only to have the tape go missing.

From left: Cameron Diaz, Ellie Kemper, Rob Corddry and Jason Segel

Claire Folger

"There's such trust [with Jason]," says Diaz. "We both had each other's backs. Our day was, 'My ass is going to be in your face and your package is going to be in my face!' "

Which took some, ahem, selective wardrobe decisions.

"We call them modesty garments," Diaz says. "My dresser and I got really intimate. Double-stick tape can be the difference between the whole world seeing your goods!"

And the subject matter certainly provided for a lot of laughs.

Says Diaz: "Sometimes I would stop in the middle of a scene and go, 'Everybody hold on! Do you realize we're getting paid to do this?' We had such a fun time laughing our asses off, having such gratitude that this is our job. We get to be idiots all day long and tell a really sweet story at the same time."