He and Kate Beckinsale spent nearly a decade together, and though they never married, they had a daughter, Lily. The couple split in 2003, but that didn't stop them from staying friends. She even said after their breakup, "I love him dearly — I would miss him dreadfully if he wasn't in my life. I've been very lucky to have two marvelous men in Len and Michael; they've got no awkward feelings about parenting Lily and working things out. I'm very proud of both of them that they haven't let any potential awkwardness or strangeness affect our little family."
Kate and Michael are even so civilized that his current flame, Sarah Silverman, has had equally amazing things to say about Kate. She told Howard Stern in September 2014 that "he and Kate are like brother and sister. They're really funny together." The family love was evident at Michael's 45th birthday party earlier this year, since both Kate and her now-husband, Len Wiseman, were in attendance alongside Sarah.