Sarah Jessica Parker and Matthew Broderick never discuss their work at home

Matthew told Parade magazine: "It doesn't come up a lot. Maybe we'll talk about it, but everybody needs a break to think about something else."

Sarah added: "It's not realistic. You walk in the door and there's three children.

Matthew and Sarah, who will be married 23 years this May, have son James Wilkie, 17, and twin daughters, Marion Loretta Elwell and Tabitha Hodge, 10, together.

In 'Plaza Suite' the pair will play three different couples at various stages of their relationships but Sarah insisted that audiences will not be able to see any similarities between the characters and her own relationship with Matthew.

She explained: "Doing a portrait of our lives has no interest to me. These characters are not familiar to us at all. Their life choices are different, and they live in a different time and place. That's why the idea of doing this was so interesting."

And she added that they are both content to keep their relationship as private as possible.

Sarah said: "It's a point of pride that there are still lines that we don't cross. So we don't talk about our marriage publicly because it's ours, and it's the one thing left that's really and truly ours.

"“We go as a family on the subway; we walk; we do everything we want to do. Sometimes people approach us, sometimes they don't. We don't want to live anywhere else or travel by cars with bodyguards."