A celebrity engagement that stayed a secret for more than a decade!

Nicole Kidman -- who stars in "Big Little Lies" with Lenny Kravitz's daughter, Zoë Kravitz -- revealed in a recent interview that she and ex Lenny were actually engaged to be married at one point. 

"I knew Zoë [Kravitz] because I was engaged to her father," Nicole told Net-A-Porter. "It’s all in the family! I love Lenny; he’s a great guy."

Nicole dated Lenny in 2003, following her 2001 divorce from Tom Cruise. She's been married to country singer Keith Urban since 2006.