More than vulnerable, it makes her ready to follow Paul upstairs into his loft apartment - the exact opposite of the house she lives in - when they have their Soho street encounter. And the inevitable machinery is set in motion.

Lane had worked with Gere when she was a teenager on The Cotton Club, so there was an element of reunion about their playing husband and wife in Unfaithful. “It was like going home,” she says. “It was shelter in the storm. So much had been asked of me, because we filmed all the scenes between Connie and Paul first, before Richard joined us.”

Given the nature of the story - a married woman drawn into a passionate sexual affair with a complete stranger - and the fact that Lyne’s previous films as a director include 9 1/2 Weeks, Fatal Attraction and Lolita, the scene between Connie and Paul could have been expected to be fairly steamy. But Lane claims that she was quite ready for this.

Olivier Martinez (Paul)

“It’s not as if I wasn’t informed as to what would be required of me,” she says, “so I was at peace with it. Incrementally, of course, you’re giving away things to the camera. I was more naked in this movie, take after take and angle after angle, than I’ve been in my entire personal life! You’ve just got to get used to it. For me, the challenge was the emotional work that was required for those scenes - the vulnerability that Connie feels, and her torment about the sexual relationship.”

Paul, the man with whom she has an affair, is exactly the kind of immoral charmer in whom Gere had more or less cornered the market 20 years ago, when he was Paul’s age. This is an irony not lost on Lyne. In this movie, he says, “it’s Olivier who is playing a character close to the Richard Gere of 20 years ago”.

Richard Gere

Martinez, best known for his roles in French movie The Horseman on the Roof and in last year’s art-house hit, Before Night Falls, insists that his character is innocent rather than immoral. “He doesn’t know what is going to happen, and he has no control over his future.” And the young French actor admits that he found the sex scenes more of a challenge than Lane did. “But this is a movie,” he jokes, “and things are faked, just like in a fight scene where nobody really gets beaten up or killed. It’s true that this was my first time doing these explicit love scenes - and it’s not my favourite thing to do, because I’m quite shy! I needed to forget myself, so I could maintain the character.

“But everybody was very nice, and we were all in the same boat, so it was fine. Adrian and Diane were very relaxed about it: I was the one who was rigid and upright! They made me more relaxed, and I think that made my character more likeable.”