Watch: David Harbour prompted to wed Lily Allen by her daughters
The actor married singer Allen in Las Vegas on 7 September, with an Elvis Presley impersonator officiating the quick ceremony.
"We got engaged right before the pandemic,” he said.
“Then the pandemic hit and nothing was happening.
"We were riding around at the beginning of the 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.
“The little one was riding along and she was going like, 'David, dad, David, dad,' because the 'd' got her confused, 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!'
“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!'
"I was like, 'I need to marry this woman.' Because the emotional fallout... "
Harbour, who is next due to appear on our screens in Marvel's Black Widow, admitted that he found the comment funny – calling it “one of the favourite things he’s ever been called”.
However, their plans for a secret wedding were scuppered thanks to the Twitter account of Clark County in Las Vegas, which posted their marriage licence online.
"Clearly what happens in Vegas does not stay in Vegas," Harbour said. "It's outrageous, right?!
“We went and registered the night before and then it broke. We were just trying to get in and out real quick."
The happy couple and both daughters later celebrated the marriage by getting In-N-Out burgers in their wedding outfits.
Watch: Black Widow trailer