The film also mixes sex and humor in a typically von Trier-ian way, such as when Gainsbourg's Joe decides to have sex with two African brothers, who come to her room and, once in the buff, start discussing what each one should do in their own language while she's seated on the bed, with a bouncing penis at either side of her. Similarly, her scenes with Jamie Bell are both shocking and crudely funny. The film has a "weird sense of humor, very disturbing," says Gainsbourg. "I mean, I was disturbed, embarrassed and a little humiliated but I wanted to go there. He didn't force me into this film, I was really willing but still, having to do that…" 

READ MORE: Why the Shorter Version of 'Nymphomaniac Volume I' Is Better Than Lars Von Trier's Director's Cut

Of course, playing a nymphomaniac implied being in several sex scenes for the actress, which, though she has done them before, she still finds difficult: "I am uncomfortable being naked. Also, I had just had a child and I was very embarrassed by the way I looked. But when I come into the part, I don't have that much nakedness to perform. All the beautiful sex is done by Stacy and I do all the nasty stuff that comes after," she says, suppressing an uneasy giggle. 

Indeed, Martin and Gainsbourg, though they play the same woman at different ages, are given very different things to do as Joe matures and explores different facets of herself. "I was worried I'd be jealous of the scenes that she had," Gainsbourg says of Martin, admitting she'd thought she might think: "‘Why couldn't I play a little bit younger?' When reading the script, it didn't say: ‘This is where you come in,' so I was really curious to know when I could start with the part."

Magnolia Pictures "Nymphomaniac"

With von Trier, who has made a lot of films with female protagonists he then puts through the wringer, the question of feminism (or its ugly counterpart, misogyny) always comes up, as Gainsbourg admits: "I've been asked this before and I, I don't know. I think it's a film about a woman portraying herself, with all her suffering and all her faults. She tries to portray herself as a terrible, bad human being and by the end, I think she understands more of who she is. It's a beautiful portrait of a woman but is it feminist because of the way she portrays her sexuality? I don't know. Maybe because it talks about a woman, that's feminist enough?"

After giving it some thought, Gainsbourg continues: "For me, the character I play is Lars so it's hard to only see her as a woman. Lars has put himself, in my mind anyway, in both Seligman and Joe, two opposite characters. That's who he is and we all have contradictory facets, different faces. So, in that sense, how is it feminist? People have said he doesn't like women but I don't see how you can portray characters with such depth and not feel for them, have no empathy? I think he loves women".

Few would argue that von Trier doesn't have an original voice and clearly Gainsbourg is attracted to working with him for the same reason: "What I find so terribly rich with him, is he…," she pauses, searching for the right words, "...he's an artist who has a compulsion, a compulsive side that wants to show us all the dark aspects of himself. So you have his sense of humor, his cynicism… He's very generous in the sense that he is willing to show it all. He's not making any compromises. In that sense he's very original and a real storyteller".

The actress also reveals a little bit about how von Trier, who refused to talk to the press after his Nazi comment at the "Melancholia" press conference in Cannes was willingly misunderstood and blown out of proportion, works on set: "Starting a scene, you don't know where you're going. It's all quite scary but Lars doesn't give you any indication. Nobody knows; the actors don't know but the cameraman doesn't know either where to go. Of course the scene is written but you can take it any place. So it's difficult because you have to dare, you have to dare being ridiculous and being bad and you are quite bad at first but then he comes in and helps".


She continues: "He doesn't do it on purpose, to make you uncomfortable at first, but he needs to see it, or that's the way he calls it, he needs to see it to then be able to articulate his ideas and explore them with you but that's what's wonderful, to have his spirit explore your character. He understands every wink you make. It's like having some read you better than you read yourself. It's wonderful then to push yourself, for the really hard scenes anyway, to push yourself to these really difficult places, to suffer a little. All of that is very exciting and so uncommon and that's why I love doing what I do. And a lot of it is thanks to him".

But working in this way isn't always easy, as Gainsbourg explains: "For each film, he has put me in a very difficult spot and asked me for something that was nearly animal-like. In 'Melancholia,' it was the last scene, he wanted something... and we shot it for three days in a row, just exploring my suffering, which was very painful and puzzling because I didn't know where to go. And again with this, it was shorter, but for the scenes where I'm recovering my orgasm, with the masochistic part, that again was really embarrassing. You know, an orgasm is an orgasm but when you have someone say: ‘Surprise me,' I don't know what to do. That was quite hard."