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Kathryn Wirsing

When you find yourself at The Crosby Street Hotel, face to face with a horn-rimmed glasses-wearing, Converse sporting Christian Slater, you might, for a moment, forget why you're there. And then you'll remember: You're here to talk about sex.

The sex in particular is that of the Nymphomanic variety, controversial Danish filmmaker Lars von Trier's two-part ode to one woman's insatiable appetites (part one hits theaters next Friday, March 21). In Nymphomaniac, 44-year-old Slater plays Joe's father—perhaps the only man with whom his pleasure-seeking daughter is not sexually entwined. "The relationship they have is very intense," he admits when pressed about the characters' strangely intimate connection. "It always stays appropriate, thank God. And never crosses the line, which I think is vital and important." And yet: "I certainly feel that the relationship with the father—as appropriate as it is and as sweet and loving as it is—she's still looking, in an unhealthy way, to find that kind of connection again."

Related: 'Nymphomaniac' Makes Me Proud to Be a Woman

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Hellin Kay

With his perennially youthful countenance, it's hard to believe that it's been 25 years since Slater stole our hearts as the original badass truant, J.D., in cult classic Heathers. (Of the forthcoming off-Broadway musical: "I'm dying to see it. The song 'My Dead Gay Son' is supposed to be really good.") His agelessness—the actor's rock hard body and wrinkle free forehead are front and center in the film's stark, character-driven promotional materials—was also of concern to the director. As Slater tells it: "My agent was in Denmark doing a lecture somewhere. He made the trip out to Lars' studio to meet with them and talk about their project. Lucky for me, he mentioned my name as a possible option to play the father. They said, 'We didn't think of that. That's interesting. What does he look like now? Will he look old enough?'" And then: "'Can he actually do this?'" So Christian Slater did what any veteran actor would do. "I borrowed some mascara from my fiancée [now wife], put some black circles under my eyes, and sent them a picture. They hired me," he says with an impish smile. "It's a little make-up trick! Maybelline number 5 got me the part."

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And while, ultimately, von Trier spares us from on-screen incest, a father-daughter pairing is about the only sexual scenario avoided in Nymphomanic. But, according to the star, the film isn't really about sex. "There's always more going on in these stories. It's definitely not porn," he says. "This is a disease. This girl is really suffering and is in a great deal of pain." Bottom line: "People are quirky. They're interesting. How we deal with issues manifests in so many, different colorful ways." As J.D. once said, "The extreme always seems to make an impression."

Photo: Kathryn Wirsing, Zentropa Entertainments/The Kobal Collection