Sarah Jessica Parker reveals Kiwi affair

Sarah Jessica Parker returns to television in Divorce, opposite Jemaine Clement.

Jemaine Clement is having an affair with Sarah Jessica Parker. At least, on screen he is.

The Flight of the Conchords star's next role has been revealed: he will play a key recurring character in Divorce, the HBO show that marks Parker's much-hyped return to television.

The comedy-drama follows Parker's character, Frances, a mother-of-two who is struggling through a divorce with her husband Robert, played by Thomas Haden Church.

Clement, last seen on the big screen in Steven Spielberg's The BFG, plays the man with whom Frances has been having a lengthy affair.

Jemaine Clemente will play a key recurring character in HBO's television series, Divorce. Photo / AP

He makes several appearances during Divorce's first season, which was created by Catastrophe's Sharon Horgan and is due to air on SoHo this year.

First reported in 2015, Clement's role was revealed only during a brief appearance in a trailer before a cast discussion at HBO's Television Critics Association panel in Los Angeles.

Parker later told TimeOut Clement's appearance was brief but "very important" to the show.

Clement's role was given to him after the scenes had already been shot with a younger actor.

"In the pilot, originally, it was a young fellow and I was like, 'I think it would be much more interesting if she was having an affair with a real man ... not a conventional piece of candy'," she said.

"I think Jemaine is such an interesting choice because he's such a wonderfully odd actor. He's so earnest ... I thought he was freaking hilarious."

Actress Sarah Jessica Parker will star in HBO's new show, Divorce. Photo / AFP

But Parker, who is making her highly anticipated return to TV after ending her six-season run as Carrie Bradshaw in Sex and the City in 2004, admits their time together wasn't so smooth.

"Jemaine is very allergic to cats and the apartment we were shooting in had been, within hours of our arrival, home to many cats," she said. "He had a runny nose, he was sneezing, he felt terrible about it. But I had fun."