Channing Tatum Had the Best Reaction to Seeing Scarlett Johansson Work with Husband Colin Jost in New Film (Exclusive)

Channing Tatum plays Scarlett Johansson’s love interest in the new rom-com Fly Me to the Moon, but when Johansson's real-life husband, Colin Jost, came to set to film a cameo, Tatum says he saw true chemistry. 

“I was like, ‘Oh, you guys are cute,’” Tatum, 44, tells Johansson, 39, during a joint PEOPLE interview.

“Yeah, I mean, I think we are,” Johansson responds.

In the 1960s-set romantic comedy, Tatum plays Cole Davis, a NASA flight director tasked with overseeing the moon landing. Johansson’s character, Kelly Jones, is a slick New York-based PR professional who’s hired to raise the public profile of NASA.

But as the moon landing mission grows closer and government officials worry a failure on that front could hurt American morale — or worse, project weakness to Russian space race rivals — Kelly is ordered to stage a fake moon landing unbeknownst to Cole.

Scarlett Johansson and Channing Tatum Pair Up for the First Time in Fly Me to the Moon First Look (Exclusive)

Jost appears briefly in a hilarious scene midway through the movie, and Johansson says director Greg Berlanti personally requested the Saturday Night Live star for the part. 

Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human interest stories. 

“[He] was like, ‘Do you think Colin would want to do…?’ Greg and Colin, they have a great rapport and they're both comedy writers and, I think, they have a little bit of a similar personality in some ways. And so I think he just really was excited to have Colin come and do a cameo. I was like, ‘Yeah, I'm sure if you ask him, I'm not going to ask him,’” says Johansson.

She also joked on the The Tonight Show July 8 that he was contractually obligated to do the movie. "And Colin, I think he had to do it because it's, like, in our prenuptial agreement."

Acting together was a treat, she tells PEOPLE: “We don't get to work together really ever because… I mean, we've worked together as he's written stuff for me for SNL, but we never get to perform together.”

Scarlett Johansson and Colin Jost Have Red Carpet Date Night at Fly Me to the Moon Premiere with Channing Tatum

Jost does, however, run lines with his wife of four years. “I was telling Channing that when I learn my lines, if he's around, of course, I'm like, ‘Can you run lines with me?’ And it's just always a thing because he'll act the other part out and [it] drives me nuts,” she says.

“He remembers all my lines also. Months later, he'll say them back to me. I'm like, ‘You're a crazy person,’” Johansson jokes.

Johansson, who shares daughter Rose, 9, with her ex, French journalist Romain Dauriac, first met Jost when she hosted SNL in 2006. They became romantic 11 years later and wed in 2020. 

The couple welcomed their son, Cosmo, in August 2021.

Fly Me to the Moon is in theaters July 12.

For more on Scarlett Johansson and Channing Tatum, pick up the new issue of PEOPLE.