Promotional sorts just love leaking stories about a film's sex factor at press junkets and what not - 'cause we'll pay to see anything with simulated sex in it. When you think about it, you're sitting in a massive dark room, with hundreds of other people, looking at two people pretending to do each other. That's a bit strange. Now, if it were real...
According to the New York Post: "Sam Mendes says directing wife Kate Winslet as she grappled with Leonardo DiCaprio in the steamier scenes in Revolutionary Road was 'a profoundly weird experience'".
Poor Sam couldn't watch it live and therefore had to take himself off to a private adjoining room which housed a separate monitor. In an interview with the Observer, Mendes said he'd holler through the intercom: "Leo, don't bang her head so hard against the kitchen cabinets!"
Sam also (tellingly) had to ask DiCaprio: "Could you not do it for so long this time? About 45 seconds." To which Leo replied: "Really? Only 45 seconds?"
You're a lucky giddle, Kate.