David Harbour has been busy.

On Tuesday night, the actor appeared on “Jimmy Kimmel Live!” and talked about starring in both “Stranger Things” and “Black Widow”, as well as how Lily Allen’s daughters inspired them to get married.

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Talking about the upcoming season of “Stranger Things”,  Harbour revealed, “You’re not supposed to say but I’ll tell you. Yeah, I’m almost done. I’ve got one more, like, little stint. We should be done in, like, August. I gotta shave [my head] again.”

He also talked about the uncanny similarities between the new season of the show, set in Russia, and the Russia-set “Black Widow”.

“I knew that I was going to be in this Russian prison and then literally a month later I got a call from Marvel that they wanted me to play a guy who starts out in a Russian prison,” Harbour said. “I was like, this is fantastic. I can’t wait to see what Twitter and Reddit and all those guys do with it. So there’s all these conspiracy theories… Hopper went to Russia and then put on a supersuit and now he’s the Red Guardian in this ‘Black Widow’ movie.”

Harbour said that he actually sent pictures from the set of “Black Widow” to the creators of “Stranger Things” to make sure they were sufficiently different.

“I kept sending these photos. And then finally at the end, I had all this hair and all this beard and we planned to do it that way and I was like, ‘Guys, we can’t do this.’ I’m coming out with this Marvel movie. I can’t have the beard and the hair. So we came up with a whole different look for [Hopper]. We had him shave his head and this whole thing.”

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Off-screen, during the pandemic, Harbour tied the knot with Allen.

“We were riding around beginning of pandemic — she has two kids, these beautiful daughters, 8 and 9 — and we were riding bikes out in the country trying to figure out what we were gonna do for the next year or however long it was going to take,” Harbour recalled. “And the little one was riding along and she was going like, ‘David, dad, David, dad.’ Because the D got her confused,” he recalled. “And the older one got very upset with that, which I understand. She was like, ‘He’s not our dad! He’s not our dad!’

He continued, “And then the younger one was like, ‘Well what is he? He’s kind of our dad.’ She’s like, ‘No, he’s not, he’s our stepdad.’ And she goes, ‘What is he?’ And she goes, ‘He’s just some guy in our lives!'”

That was apparently the final straw.

“I was like, ‘I need to marry this woman,'” Harbour laughed, “because the emotional fallout … ”