In Bad Santa your character Sue really, really likes Father Christmas. How do you prepare for a role like that?

It was all very strange. I had to audition doing the scene where I first straddle Santa. So I’m basically in front of a room full of executives humping a chair. I really did love Billy Bob though, even more than the chair. With a character like this you have to make a big decision. I just thought: she loves anything to do with Christmas, she totally doesn’t see what’s disgusting about this particular Santa. He fulfils a strange kinda fantasy for her. Plus, y’know, I’m on The Gilmore Girls here in the States where I’m known as a very talkative, verbal, cerebral character, so this was a huge relief in a way. This is a girl who’s just totally impulsive and goes with her guts. And Christmas just makes her very, very happy!

Is this the least sugary Christmas film ever made?

Yeah – I think a lot of people relate to it, to its negative view of the holidays. I mean, Billy Bob’s guy embodies every piece of resentment we have to the enforced jollity, all wrapped up into one. He’s just wonderful – somewhere under there is some kind of warmth, that’s what makes the film work. It makes it OK that he’s angry and awful and mean. Do I hate Christmas? I fall somewhere in between. I enjoy it, but I also get the movie ‘s misanthropy. I don’t like sentimental films. The sense of humour here is very dark. But it works.

You and Billy Bob and the weird kid form a bizarre kind of nuclear family eventually.

Yes, in our own strange way. Billy Bob is one of my favourite actors. He’s very generous, he found just small ways to make our relationship really specific. He lets you try things, goes: yeah okay, let’s see if that flies. It’s weird when you work with a movie star, cos you can sometimes get too nervous to do your own thing.

Really? But you’ve worked with Keanu! With Meryl! With, er, Renee Zellweger.

Sure I’ve done a few movies, lots of things, but in this case I really look up to Billy Bob. You need help sometimes to get over your own brand of starstruck craziness. When I did a film long ago with Meryl Streep – One True Thing – I basically couldn’t complete a sentence around her! Thank God Billy was so warm, cos as you can see in the film I had to be warm around him, hur hur.

How’s working with Terry Zwigoff?

Well I’d loved Ghost World. Terry’s just always positive. One of the surprises of the movie was no-one knew how it was gonna turn out. I mean, on the page, on the script, it was really, really vulgar! And yet Terry and Billy were both so sweet. But I still think it’s really really dirty. The humour carries it off. My father is totally appalled by it.

How come it did so well in The States? Bit “edgy”, surely?

Everyone was surprised by how well it did here. There was a fear, sure, but maybe people were saturated with soft, sweet, sentimental films. This tapped into an audience that’s perhaps been under-represented. I think we Americans are just as bitter as you Brits, y’know. That’s what we’re learning here, huh? Or we’re trying, in our way, making an effort to be as bitter as you guys!

Good luck with that. What’s up next for you?

I’ve done two films this summer. One is The Pacifier, with Vin Diesel. Is it action? You bet. Except it’s a family movie, sorta like Kindergarten Cop. Shut up. I did get to do one stunt, which was very thrilling for me. And lived to tell the tale. I’d felt insulted cos when I arrived on set I expected them to inquire if I intended to do any of my own stunts, but they’d already hired a stunt person without asking me. So with foolishness disguised as professional pride I dove in. And then there’s a movie with Jeff Bridges called The Moguls. More of an indie story about a smalltown loser, Jeff, who decides to make a porn film to make his family proud of him. Obviously I’m really attracted to smalltown losers. Just like Bad Santa, Jeff’s guy does some really perverted things in an effort to find personal triumph.

You almost won a Golden Globe?

Almost, yeah. Which is like – I lost. You don’t get The Gilmore Girls there, no? But you get Law And Order, I was in that. My mother lives in London and it’s always nice when anything I do comes out there, with the possible exception of Bad Santa. Otherwise I’m shipping her tapes of my show by the boxload. It’s doing well, and hey it’s great to have an acting job in the age of Reality TV.

By Chris Roberts