Amanda Seyfried's sex scenes on 'Chloe' left her cold.
She said: "It was unnatural - I say that with a grin. Seriously, it is not the type of scene any actor is ever comfortable doing. Any kind of intimacy is strange. It is not your partner; it's the actor or actress.
"I don't know what goes through my mind when I do these scenes. I am listening to Atom's technical directions, because things need to be iN Sync with the camera's movement."
The 'Mamma Mia!' star also admits she managed to get out of doing some of the nude scenes she was required to do.
She told website News Shopper: "I definitely negotiated my way out of some stuff. It is perfect.
"That's the thing. At the end of the day I knew I would do whatever Atom needed from me in terms of nudity, but I knew he wouldn't need much because he doesn't really like to use it that much. He is a little uncomfortable with nudity."
The movie tells the story of a Doctor Who hires an escort to seduce her husband, only to end up in a complicated love triangle.
'Chloe' is released in the UK on March 5.