David Harbour has found being a stepfather the "hardest thing" he's ever done.
The "Stranger Things" actor has a "really, really special" relationship with Ethel, 10, and nine-year-old Marnie – his wife Lily Allen's children with her ex-husband Sam Cooper – and he has learned a lot about himself thanks to the bond he's built with the girls.
He said: "I’ve learnt a lot about myself. You really have to show up for other human beings in a truly selfless way. I was, like, ‘Whoa, this is the hardest thing I’ve ever had to deal with’.
"The relationship I have with them now is really, really special. But, you know, it takes time and effort.”
While David gets recognised more than his singer spouse when they're out and about in New York, where they now live, the roles are often reversed when they are in the UK, and he and the "Not Fair" hitmaker like to tease one another about who is the most "famous".
He told the Times newspaper: “Yeah, we like to make fun of each other when that happens: ‘More famous than you today.’ "
The 47-year-old star used to question why celebrities dated one another, but he's grown to realise it helps his relationship that both he and Lily understand the fame game.
He said: “One of the things that we share in the partnership, though, which is unique and great, is the fact that we understand that game. There is a game to fame on all levels and I’ve been in other relationships where there wasn’t that understanding.
“And it definitely deepens the relationship: it’s not a thin, shallow thing, there’s a deeper shared experience that brings us together and keeps us connected.”
The "Revolutionary Road" actor always wanted to be famous, but after "Stranger Things" made him a household name, he's discovered it's not quite the "champagne party" he expected it to be.
He said: “Fame is a funny thing because I used to really, really want it. I’d say to my method acting teacher, ‘I want to be a famous movie star’, and they’d go, ‘No, you need to do theatre!’, I’d go, ‘No, you don’t get it, I want to be a famous movie star, I want to be Harrison Ford'.
“And then, I mean, I’m not Harrison Ford, but I got here to a certain degree. And I remember talking to famous people along the way, they’d go, ‘It’s really fun with your high school friends, all the people who beat you up in high school, you get to say, "I’m famous now." But that’s about it.
“And I did not believe that. And then I was, like, ‘Oh, I get it now’. It’s a much weirder thing than I thought it was. It’s not the champagne party that I envisioned in my head.”