Adam Rapp received a Pulitzer prize nomination and an Obie award for his play when it debuted in New York; much of the comment focussed on the realism of its sex scenes.

Davis and Matt are sharing a room in Amsterdam, and Davis brings a hooker, Christina, back, to get Matt laid. Matt falls for Christina, but Christina falls for Davis. It's a classic love triangle, squeezed into a pokey motel room and, later, a New York apartment.

Rapp directed the original production, as he does with many of his plays. They aimed "to make the whole thing really real, and not shy away from it in any way", he says.

"It looked very much like actors were truly having sex on stage. These are the kinds of things that happen in the privacy of the bedroom and bathroom.

When we see these things on stage, we forget that we're in the theatre. The great challenge to the actors and director is to make the audience feel voyeuristic to watch that."

Rapp is speaking on the telephone from New York.

He is supposed to be here for the opening night of this, the European premiere of Red Light Winter, but injured himself playing basketball and can't travel.

(There's "a real disdain for the jock" in the theatre community, but it doesn't bother him, nor does the fact that 39-year-olds perhaps shouldn't be playing in a semi-pro league. He's addicted. "I'll be playing in my 60s if I can.") It's not easy letting his plays out of his hands, especially when he can't even see the production.

He's had bad experiences before. In the introduction to his play, Nocturne, a 95-minute monologue, it states that there should not be an interval - in a production in Cincinnati, the actor took a break. In an acclaimed production of Blackbird in Chicago, the lead actor took liberties with the text. Rapp was "really shocked, really disgusted", and refused the company rights to further plays.

"I think of all these plays like my kids - letting them go is like letting someone else dress them up for Hallowe'en, or something."

That's a lot of kids - he's written 30 plays (as well as seven novels). Is he, perhaps, a little too precious?

"I think I am sometimes. I know I have to let that go."

Purple Heart is now the resident company at the Mill, and Red Light Winter is their first production to get full Arts Council funding. "It makes a real difference, " says their artistic director, Stewart Roche. "People don't have to go and do their parttime jobs after rehearsals."

Roche is on stage in this production, playing Davis, described by Rapp as a "sexual carnivore".

The sex scenes are difficult, he says, but ultimately it's all about technique. And Davis "gets off lightly", he says. He doesn't appear to mean that literally. His mother is attending on Thursday, though he doesn't think she's bringing as many of her friends as to their previous productions.

The obvious question for Roche: is he playing to type? Speaking on the phone, he jokes, "it wouldn't be the first time I've played this kind of part". Minutes after the call ends, he sends a text: "My girlfriend will execute me if she reads the piece and I don't deny playing against type on the sexual carnivore front.

Will you add it in and save my ass?" Done, Stewart - though it might be easier to save your ass if you weren't baring it on stage.

'Red Light Winter' is at the Mill Theatre, Dundrum Town Centre until June 23. Booking (01) 296-9340