Sarah Jessica Parker Photo by: Sylvain Gaboury / FilmMagic
Sarah Jessica Parker: My Son Is the Boss | Sarah Jessica Parker
With a Sex and the City movie now looking like a reality, Sarah Jessica Parker is still keeping motherhood a priority.

"James Wilkie is so conscious now of the time we spend together," Parker, 42, tells August's Elle of her 4-year-old son with Matthew Broderick. "I try to be home to tuck him in at least four nights a week, and if I'm not, he's not letting me get away with anything."

And he definitely knows what he wants. "The other night I was sitting with him on the steps before Matthew and I went out to the theater," says Parker, "and he looked at me and said, 'Mama, this has got to stop. Go upstairs and take that dress off.' "

Parker, who balances a heavy workload as an actress, fragrance developer and clothing designer, also shares her formula for making her 10-year-marriage successful: She and Broderick keep their lives out of the spotlight.

"Actually," she says, "it's not hard to be a private couple. I see some people who actually do it really well, and then I see people who make me skeptical about their deep desire to be so private. It's like, 'Are you sure that's what you really want?' "

One way they avoid having the marriage placed under a microscope, she says, is to avoid walking down a red carpet together. "That's where they get you," she says. "Suddenly it becomes, 'Oh, when are you guys going to have another baby?' "

Although their marriage is a rare Hollywood success story, she says, "We try not to talk about the relationship. It's not that we're not proud; it's just that's the kiss of death."

Sarah Jessica Parker: My Son Is the Boss| Sarah Jessica Parker
As for what stalled the Sex and the City movie for three years after the series ended, Parker says: "I really wanted it to happen, and it was a bitter pill to swallow that it didn't. ... One of us didn't want to do it at the time, meaning Kim [Cattrall], for reasons that I didn't ask. It's not for me to talk anybody into anything, ever."

A rep for Cattrall tells Elle that the actress "will address it when the time is appropriate."