Sarah Jessica Parker thinks a successful marriage requires ''a lot of vitality''.

The 'Sex and the City' beauty has been married to actor Matthew Broderick, 55, for more than two decades, and she has revealed how they've maintained their romance.

Speaking to People magazine, she said: ''I think marriage has a lot of vitality. If you're fortunate, it's like this dazzling organism.''

The 52-year-old star married Matthew in front of 100 of their closest friends in May 1997, and they have since become parents to twins Tabitha and Loretta, eight, and 15-year-old son James Wilkie.

While she had never really thought about marriage, Sarah realised Matthew was probably the one when she found herself wanting him to propose.

She shared: ''I never thought about a wedding dress. Never. Had not one daydream about it. At one point I just simply remember thinking, 'God, I really hope he asks me to marry him.' I don't know when or why. It was fairly early on.''

Meanwhile, Sarah has recently come under fire from her former 'Sex and the City' co-star Kim Cattrall.

The actress accused Sarah of ''exploiting'' the tragedy of her brother's death when she sent her condolences to Kim.

The harsh words came after Sarah left a comment under the Instagram post which confirmed Christopher's death, in which she offered her condolences to her former co-star.

The 'Police Academy' actress took to Instagram again a few days later to slam Sarah, writing: ''My Mom asked me today 'When will that @sarahjessicaparker, that hypocrite, leave you alone?' Your continuous reaching out is a painful reminder of how cruel you really were then and now.

''Let me make this VERY clear. (If I haven't already) You are not my family. You are not my friend. So I'm writing to tell you one last time to stop exploiting our tragedy in order to restore your 'nice girl' persona. (sic)''