Keira Knightley had to drink vodka to pluck up the courage to shoot her spanking scene in A Dangerous Method.
The 26-year-old actress was worried about the racy sequence from the first time she read the script, and admitted she needed to have a stiff drink before filming started and admits she is not keen to repeat them.
Speaking at the Toronto Film Festival, she said: "I did a couple of shots of vodka - definitely - beforehand, and then a couple of glasses of champagne as a celebration of never having to do that again."
The film - made by controversial director David Cronenburg - is an examination of the relationship between psychoanalysts Carl Jung and Sigmund Freud - played by Michael Fassbender and Viggo Mortensen respectively - and Keira plays Sabina Spielrein, a Russian who has an affair with Carl.
Keira was so nervous about the erotic scene, she even threatened Michael beforehand.
She revealed: "I did actually say to Michael before one of the scenes, 'I've got a security guard outside. You touch me and he's gonna break your legs!'