Matthew Broderick and Kyra Sedgwick used to date each other at school.
The pair have confessed they were in a relationship during their teenage years and used to skip classes to indulge in a sneaky cigarette in the education establishment's stairwell.
They said: "[We] went back and forth for a few years."
But they insisted they never sealed the deal in the bedroom.
During a joint appearance on 'Watch What Happens Live', host Andy Cohen asked if they had known each other "connubially", but Kyra - who wed Kevin Bacon in 1988 - replied: "Never before I got married."
Matthew - who has son James, and seven-year-old twin daughters Marion and Tabitha with Sarah Jessica Parker, his wife of 19 years - got so close to Kyra during their younger years he knew her mother Patricia, who was sitting in the show's audience.
'Sex and the City' star Sarah is pals with show host Andy and he often accompanies her to the Met Gala, but Matthew admitted people have poked fun at him for letting his wife go to the star-studded event with another guy.
He said: "One time [people] said there was something wrong with that, so I said, 'I should go now,' and she said, 'No, I like when Andy takes me.' "
Kyra - who has kids Travis, 27, and Sosie, 24, with Kevin - added: "It is boring. I only went once and I was never invited back."