R-Pattz says acting out vampire sex isn't easy

Robert Pattinson admits he and Kristen Stewart had a difficult time filming an intimate sex scene in the final Twilight film.

He and Kristen, 22, had to work hard to make the sequence appear realistic without making it too raunchy for younger audiences.

‘The sex scene is pretty ridiculous. It’s just because you’re kind of shooting stuff to be PG-13…it’s just trying to think of inventive ways to make something sexy,’ says Robert, 26.

‘It can’t just be a normal sex scene. It’s supposed to be about, like, the greatest vampire sex you’ve ever had.’

Robert – who took Kristen back last month after she admitted to cheating on him in July – says he and his girlfriend were instructed to show faces of ‘ecstasy’ during shooting.

It was a little embarrassing for the real-life couple to act out reaching climax in front of the film crew.

‘We’re doing it just to the camera, and the camera man is laughing as well,’ Robert tells Australian radio hosts Kyle and Jackie O.

‘Guys faces I don’t think are really designed to do [that].’

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Anna Duff