Robert Pattinson's sex scene with Julianne Moore was ''sweaty''.

The 28-year-old actor got intimate with the actress in the back of a car in their new movie 'Map To the Stars' and he says shooting the raunchy moment was a ''wonderful experience''.

Robert was quizzed on who was the ''better passenger'', Julianne or Juliette Binoche, who his 'Cosmopolis' character had sex with in the back of a limousine, prompting him to blush and giggle before composing himself to answer.

The actor - who was seated next to Julianne at the Cannes Film Festival press conference - responded: ''They are both like sevens...

''Obviously, Julianne. It was a wonderful experience, just extremely sweaty.''

Meanwhile, the British star has ruled out ever reprising his 'Twilight Saga' role of Edward Cullen in the future.

He insisted to Variety: ''I couldn't do another 'Twilight' movie. I'm too old.''

Robert previously admitted his 'Cosmopolis' sex scene was awkward because of the confined space in the car.

He said: ''There's not enough space to really do it. So she's banging her head on the ceiling. It ended up being kind of funny. But it's supposed to be kind of erotic.''