Mila Kunis, Ashton Kutcher can't stop laughing in Jimmy Fallon video

'I'm awful at this': Mila Kunis, Ashton Kutcher can't stop laughing in Jimmy Fallon's voice swap game

Need a laugh? Mila Kunis and Ashton Kutcher have a few to spare.

The famous couple made a virtual appearance Tuesday on "The Tonight Show" to share an update on how they've been passing the time during quarantine. But a twist in the interview rules meant they couldn't stop laughing. 

As host Jimmy Fallon explained, Kutcher and Kunis would take turns playing the role of ventriloquist dummies. After he asked Kutcher a question, Kunis answered for him while he was left to move his mouth, and vice versa. 

The couple traded goofy lines: Kutcher, as Kunis, detailed her morning bowel movements; Kunis, as Kutcher, shared an affinity for children's music.

"Are you even playing the game?" Kutcher asked his wife at one point, as she sat back in her chair, wiping away tears from laughing so hard.

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Mila Kunis as Jackie and Ashton Kutcher as Kelso in a 2003 scene from "That '70s Show."

"No, I'm awful at this," she replied. "I don't know how people keep a straight face. Do you know my worst fear – and I've said I'll never do it – is 'SNL' because of this. I clearly enjoy laughter and I have a very hard time holding it down."

Kunis reminded her husband of their time on Fox's "That '70s Show," during which the crew would "always get mad" at her for laughing while filming. 

"You and Jimmy on 'SNL' would have been a great pair," Kutcher cracked as Fallon, notable on the sketch show for breaking character, launched into another laughing fit.