The camaraderie between Johnson and Wayans is apparent on screen. And also in person, during a promotional stop they made in Philadelphia. The two are so in sync, so attuned to each other's sense of humor, that it's a constant race to see whether either can get to the end of a sentence before they both crack up.
"I feel like we definitely have a very similar sense of humor," says Wayans. "We're definitely always down to laugh. If I'm in a bad mood, he makes me laugh. If I'm in a good mood, I'm laughing before he opens his mouth. I feel like that bled into the movie."
It's a relationship forged by constant togetherness.
"The reality is we spent all of last summer together making this movie," says Johnson. "Then we spent all year together doing the TV show. Now we're doing press for this movie all summer, then we'll go back to making the TV show all year. It's getting weird."
"It's already weird," says Wayans.
The two play off each other so well that they had no problem swapping roles just before shooting started.
"Somebody at the studio called and said, 'We'd like to see you switch. Do you guys mind?' " Johnson recalls.
"We absolutely didn't," he continues. "It's not like it's a straight-guy funny-guy movie. We'll make every scene work either way."
The only problem with the trade-off of characters is that you now have to buy the unimposing Johnson as a former star quarterback at Purdue who was a lock for the NFL.
"Hey, I'm really good at basketball," says Johnson, defending his athleticism. "I'm also a really good wrestler."
"Now that's weird," interjects Wayans.
"But not trained," says Johnson. "I'm more of an instinctual grappler." The two howl with laughter.
Let's Be Cops calls on Wayans, 31, to perform in a more physical, slapsticky style than he has before. But he feels that growing up in the Wayans' showbiz family circus ( I'm Gonna Git You Sucka) gave him a foundation.
"My father early in his career was a very physical standup comedian," he says. "Jim Carrey was one of my dad's best buddies. He was always around doing crazy stuff."
Until his big break on New Girl in 2011, Johnson, 36, existed mostly on the fringes of the business, doing any kind of job he could get so he could afford to keep auditioning.
"I didn't have a backup plan," he says. "Believe it or not, I'm not the sharpest tool in the shed." The two men start helplessly guffawing.
"I worked for a caterer at some big event [attended by] Natalie Portman. I was one of the people with the trays giving everyone food," Johnson recalls. "I later worked with Natalie Portman [on the film No Strings Attached] and I wanted to be like [breaking into a taunting singsongy voice], 'I know what kind of appetizers you like.' "
"Two olives, right?" counters Wayans.
"And you're going to need this napkin over here," adds Johnson, "because Natalie Portman - you're a mess." More laughter erupts.
Clearly, the costars of Let's Be Cops aren't feeling a lot of pressure in the days leading up to the film's release.
"It's not like we're big-enough stars," says Johnson, "that if the movie tanks, people are going to be like [shifting his voice to bellowing outrage] 'What? The new Damon and Jake movie didn't work?' "
"It's not like they paid us a lot of money to make it," he says, and both men collapse in hysterics.
Let's Be Cops
Opens Wednesday in area theaters.