The 45-year-old actress, who tied the knot with the James Bond star in June 2011, said she wants to "protect" their relationship from the public eye, reported Hello! magazine.
"He's just too famous. It would be a betrayal. You have to protect your marriage. When you're young, you tell your girlfriends everything. One of the great pleasures of not being an adolescent is that you don't have to share everything.
"When you're married, that door closes. The audience goes, and you're in your own life," she said.