Kate Beckinsale and Michael Sheen's "really similar sense of humour" makes them good co-parents.
Kate Beckinsale
The 'Love & Friendship' star - who has 17-year-old daughter Lily with the 'Masters of Sex' actor - has always maintained a good relationship with her former partner for the sake of their child.
Asked what the secret is to their longstanding friendship, she said: "Well one, pick well. And two, I think we both really felt like, we really agreed on what would be the right thing for Lily. And I think, you know, not hating each other and fighting and all that would be awful for her.
"I think we've also got a really similar sense of humour, and I do find that humour can save an awful lot of things and help a lot of things. I just really like him. He's family. I've known him since I was 21, so he's proper family now."
And Kate, 43, regularly spends time with Michael and his current partner Sarah Silverman and the group tend to spend Christmas and Thanksgiving together.
She added to Entertainment Tonight: "Well, we had Thanksgiving at his girlfriend's house and they're having Christmas at our house. We like hanging out with each other, so it's not like, 'Oh, who gets Lily?' or whatever. It's like, 'Whose house are we going to be at?'"
The family have had a lot to celebrate recently after Lily was accepted into college.
Sharing a picture of the exes emotionally hugging, Kate wrote on Instagram: "The appropriate fatherly response when you find out your girl got into college: burst into tears, drop everything, rush over and pick up everyone even remotely involved . @lily_beckinsale we are so unbelievably proud of you . Fly fly fly (sic)"
Tagged in Kate Beckinsale Michael Sheen Sarah Silverman