Kidman and Kravitz did get engaged during the time between her divorce from Tom Cruise and subsequent marriage to Keith Urban, when they dated in 2003.
The Big Little Lies actress let the secret slip when she was discussing her HBO costars, specifically Zoë Kravitz.
"Well, I knew Zoë because I was engaged to her father. It's all in the family!," the Oscar-winner told NET-A-PORTER.com's magazine, The EDIT. "I love Lenny; he's a great guy."
While their relationship didn't work out, the two artists remain friends. She and Urban have been spotted hanging out with Kravitz at events on multiple occasions.
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