Sarah Jessica Parker says she doesn't understand relationships.

The 'Did You Hear About The Morgans?' actress - who raises three children with her actor husband Matthew Broderick - insists she isn't a good person to go to for romantic advice, despite being married for 12 years.

She said: "What's the secret to a successful relationship? Oh I'm no relationship expert I've no idea. You should speak to someone with a doctorate if you want advice!"

The 44-year-old screen beauty was in London's Leicester Square Tuesday night with her co-star Hugh Grant for the Gala Premiere of the romantic comedy, in which they play a married couple who battle to rekindle their romance.

Despite the cold and wet weather, Sarah looked stunning as she snuggled up to Hugh for photographs while wearing a hot pink dress and sky-scraper heels. She said: "I'm loving London. I always love London. Am I cold? Oh God, compared to New York, no I'm not. It's practically mild!"

Sarah and Matthew had twin daughters Marion Loretta and Tabitha Hodge via a surrogate mother in June, and the 'Sex and the City' star admits they are "wonderful".

She said: "The babies are very wonderful. Filming this was a long time to be away from home but, you know, I don't want the time back."

Sarah also revealed she loves visiting London because the people are so "sophisticated".

She explained: "I love this city. I've loved it since I was a little girl. I remember the first time I came here in 1976 when I was a little girl and I always thought, 'When I grow up I'm going to move to London, because everybody there is so sophisticated.' "