Actress Keira Knightley has revealed she issued co-star Michael Fassbender with strict instructions not to touch her while filming some kinky scenes in A Dangerous Method.
The Pirates Of The Caribbean actress plays real-life psychoanalyst Sabina Spielrein in the David Cronenberg film about the birth of psychoanalysis, and had to film several sex scenes with Irish actor Fassbender, who plays Carl Jung.
One particularly risque scene sees Jung spanking Spielrein - but, speaking at the UK premiere of the film at London Film Festival, Knightley said it was all just pretend.
"I actually said to him before we shot the spanking scenes, 'If you touch me I will kill you' and he did remind me that I was tied to a bed at the time and really I shouldn't be making any threats," she said.
"The film is about so much more than S&M but [those scenes] weren't particularly easy," Knightley added.
The actress, who wore a monotone dress by Roksanda Ilincic and towering Salvatore Ferragamo heels, added that watching the nude scenes was "strange" but that the job was a "dream come true".
She added that she likes to vary the roles she takes on, saying: "It's important to push yourself. I don't want to do the same thing again and again and again and I don't think people really want to watch that, and sometimes I'm going to fall flat on my face and I think I have done that, and will continue to do that but hopefully there will be some gems in there that are really interesting as well."
Canadian director Cronenberg praised Knightley's range. He said: "I think she's underrated as an actress... I was always looking forward to working with her and I never offered this role to anybody else."