The former That 70s Show star insisted it was "terrifying" to wake up and hear voices.
He said: "She's watching in the middle of the night, and I didn't know what was going on. I was like, 'Is there someone else in the bed?' It was terrifying!"
Kunis added: "I was like, 'Shhh, quiet, this is a wedding!' "
Kutcher jokingly accused his wife - with whom he has children Wyatt, 6, and 4-year-old Dimitri - of having an affair because of her love of the programme.
He quipped: "You're cheating on me with this show."
Meanwhile, the couple will star together in a Super Bowl commercial for Cheetos and Kunis recently admitted one of the reasons why they agreed to shoot the ad was because it gave them some "freedom" away from their children.
She said: "In the midst of quarantine, they sent us this ad to do, and every time I've ever been offered a Super Bowl ad it's always a female having to be scantily clad.
"And this one comes around, I started laughing so hard and Ashton was like, 'This is kind of funny.' And I was like, 'We should do it!'
"Also it was quarantine and we were stuck with our children for nine [or] 12 months at this moment, and I was like, 'Two days, baby! Two days off!'
"Literally we were like, 'Yeah, okay, let's do it.' And so we did it. And I hate saying it but we were like, 'Freedom!'"
