Keira Knightley had to practise her 'sex face' for hours before demonstrating them to David Cronenberg via Skype, she's told The Sun. In her new movie A Dangerous Method, directed by Cronenberg, Keira plays a patient of the famous psychiatrist Carl Jung. Her character, Sabina, forms a sado-masochistic relationship with Jung, who is played by Michael Fassbender.

Keira told The Sun that she had to research the role by speaking to psychoanalysts about Sabina's condition and they said "Sex and anything like that is trying to release energy. So I worked with that and sat in my bathroom and pulled faces at myself for about two days, trying to figure out what it was going to be." Then, she said, she set up a video conference call with Cronenberg to demonstrate the array of 'sex faces' that she had conjured up. She admitted that, at first, the spanking scenes had put her off taking part in the movie, despite her desire to work with Cronenberg (the director responsible for Crash and A History of Violence). Cronenberg offered to take the scenes out, if it meant Knightley agreeing to the role but the Bend It Like Beckham actress "realised they were integral to the piece, that it was really important to see them and show that within the study of that relationship."

A Dangerous Method opened in the United States in November 2011 and is scheduled for release in the UK next week (February 10, 2012). Keira is also scheduled to feature as the title character in the 2012 adaptation of Anna Karenina.