Jo Hartley says her audition to be in Bliss went very smoothly and she jumped up and down in joy when she got the part.

What drew you to this project?

I've been doing a lot of comedy recently, and I thought I wanted to do something serious. Then my agent sent me these scripts. I read them so quickly - bang, bang, bang. The writing was so pacey. It was fun, offbeat comedy, and I was immediately gripped. I couldn't say no.

All the main characters are written very fully. It's not just about one person, it's about all of us as a group and how simple, bad decisions made in the heat of the moment can affect a whole variety of people. As human beings, we all make decisions that come back to bite us in the ass. This comedy is saying we have to own things and take responsibility for our choices.

So how did the audition for Bliss go?

It was one of the best auditions I've ever done. At the end of it, David [creator David Cross] said to me, "I have no notes". I was made up because David is a genius. Then I had a chemistry reading with Stephen [Mangan], and he said to me, "You were amazing". I came out floating.

Soon afterwards, the producers called me and told me I'd got the part. I was at my mum's in Manchester, and I remember just jumping up and down for joy!

Can you please describe Denise to us?

I really like Denise - I immediately identified with her. She's feisty and doesn't want to conform to the patriarchy. She's quite bohemian, arty, unconventional, rebellious, outspoken and cheeky. She is quite rough and ready. All women are strong, but she is a particularly focused, positive woman.

What is her background?

She and Andrew met and fell in love at university, and she became pregnant. Her wealthy parents disowned her because of her partying, and now she doesn't drink. She's trying to change. She's frustrated, and wants to do something with her life.

Why does this subject work so well as a comedy?

It's a very clever topic to tackle in comedy. It gives it an edge, and some people might be surprised by it. What is particularly clever is that Andrew is so likeable. It wouldn't work if he was simply an asshole.

What do you think motivates Andrew?

He isn't a bad person. He didn't intend any of this to happen. He loves both women. He is genuinely trying not to hurt anyone. But he is not taking responsibility for his actions. He is being dishonest. He shows very human flaws - dishonesty, resentment, fear, jealousy, anger - because he's chronically frightened of being found out. He is suppressing fear and shame because he knows they eat you alive.

How did you and Heather Graham get on?

We have become very good friends. She's a beautiful spirit. I have visited her in LA and New York. She is a very calm, centred person. She's very focused, professional, talented and quick. When I heard she had been cast as Kim, I thought, "Wow, Heather Graham from Boogie Nights? How's that going to work?" Then I said to myself, "Just go with the flow." It has actually been an amazingly clever idea to cast Heather. She's just brilliant.

What makes David such a good writer?

It is very hard to find good comic scripts, but Bliss immediately stood out. David is very down-to-earth. What you see is what you get with him. You expect comedy to be more obvious, but Bliss has so many twists and turns. David has injected drama and darkness into it. He's also very good at writing female characters. They are all very real, witty and intelligent.

I also love the fact that David weaves different stories into the narrative so well. Heather and I each have the lead in three episodes as David alternates stories.

How did you find working with Stephen?

He's such an amazing actor. He's very intelligent and down-to-earth. He doesn't take himself too seriously, but he takes his work very seriously. He's always very prepared, positive and kind. He is fantastic at thinking on his feet and always gives you tremendous support. He's a lovely person to work with.