The Sex And The City star has just begun rehearsals playing a fading Hollywood star who battles drug addiction and seeks comfort in the arms of a young gigolo in a new production of Tennessee Williams' Sweet Bird Of Youth at the Old Vic.
Kim revealed: "I was doing Private Lives in the West End about two years ago and Kevin Spacey came to see it and he took me for lunch a few days later and said 'I have an idea'... he said 'Sweet Bird Of Youth'. And I said, Alright, if you can get Marianne Elliott to direct it I'll do it - and he did!"
Marianne is an award-winning British director who has worked on acclaimed productions in the West End and Broadway.
Kim, 56, admitted Sweet Bird Of Youth was not a light-hearted play, but promised the production would be sexy.
She said: "Every play is a journey. Antony And Cleopatra isn't a comedy in three acts either, at least this woman doesn't die with a snake at her breast. I think it's a beautiful journey for both of them, and somewhat of a love affair really, because I think these people in some ways, who are discovering all of this are maybe meant to be together.
"And it's very sexy too!"