She's done quite a few nude scenes, as well as posed sans clothes for magazines, but
Sienna Miller insists that "gratuitous nudity" makes her uncomfortable.
The actress, who admits that she has dropped her clothes "an awful lot" of times, insists to men's mag Esquire that doing so doesn't mean that she is comfortable with it.
"I'm not comfortable with gratuitous nudity - although I have done an awful lot of it in my career," The Sun quoted her, as telling the mag.
Miller, in the meantime, though extremely excited about the release of her new movie 'Factory Girl', revealed last month to the Daily Mirror that she is a little worried about the film's explicit sex scenes, which she says are sure to make her father cringe.
Miller, who portrays counter-culture icon Andy Warhol's muse Edie Sedgwick in the film, insists that though the sex scenes needed to be graphic so that they would seem real, she is still extremely nervous about her father's reaction.
"We wanted to make it realistic and I watched it thinking 'Oh my God, my Dad's going to see it!' And that was going through my head," the Mirror quoted her, as saying.
In the film, Sienna's steamy scenes are with Hayden Christensen who portrays a folk singer based on Bob Dylan, who had an affair with Sedgwick, but who movie bosses have given another name for legal reasons.
However, the British beauty insists that the scenes needed to be graphic, for anything less would have seemed out of place in the movie.
"But it was relevant to the story in that it's a movie about the 60s, and sex and drugs and rock and roll were a big part of that. We didn't want to hold back because it is a real film and it is a gritty film and there was a lot of shocking things and it wouldn't fit in the film if we had an unrealistic sex scene. It was always a bit uncomfortable but I think it was relevant to the story," Miller revealed.
"I also believe that there's nothing worse than seeing a sex scene where someone's got a T-shirt on because it's unrealistic so I think that if you're going to do it, do it," she added.
Couple of Sienna Miller nude pictures from one of her gratuitous nude scenes.