She is about to open in Beautiful People, a new play by Neil Monaghan, at the Stephen Joseph Theatre in Scarborough. Last night I was at a girlfriend's and we were drinking rum punch and suddenly at midnight we decided she had to cut my hair So she took to it with shears and now it's all hacked off. I haven't been to a hairdresser's for a year because I can't bear paying to sit in a chair and be primped. Tomorrow I'll have to go to work and account for my hair with the director. I'll have to make it some clever thing to do with my characterisation.How are rehearsals going?I'm obsessed with the play. It's all about anti-globalisation, and I play a businesswoman ripe for conversion.

For research, I'm re-reading The Silent Takeover by my friend Noreena Hertz. I was meant to be going on holiday with Mariella [Frostrup] as a treat after filming Coupling, but when this play came up, I had to take it.Could you let us in on the plot twists in the new third series of Coupling?I get to snog Lloyd Owen, which is a real perk. He plays a celibate religious broadcaster while Jane, my character, is an absolutely out-there nymphomaniac. So there's a lot of comic potential in her trying to shag him.

Jane has spent so long pursuing Jack Davenport I'm glad she actually gets a boyfriend.Your character Jane is bisexual. Have you ever thought you might be?No, I've been less than adventurous in that department. But very early on in my friendship with Mariella, I saw her at a party at the Ritz, and remembered I'd dreamt that I'd kissed her. There was definitely a frisson, but it just gave us the giggles, really.