The husband and wife team behind 'The Fall Guy' reveal how their own love affair inspired stars Emily Blunt and Ryan Gosling

• "The Fall Guy" director David Leitch and producer Kelly McCormick are a Hollywood power couple behind the scenes.
• The ex-stuntman and producer related to the story, about a stuntman working with his former flame.
• "A lot of the truth is stranger than fiction; people have romances on sets and fall in love," Leitch told BI.

David Leitch and his wife and producing partner Kelly McCormick aren't household names, but the action movies they've made over the last five-plus years certainly are.

With films like "Deadpool 2," "Fast & Furious Presents: Hobbs & Shaw," and "Bullet Train" earning them hundreds of millions at the box office, the duo has become a powerful couple behind the scenes in Hollywood.

Their latest film, "The Fall Guy," looks to continue that streak of success. In many ways, it's also their most personal project to date.

A reimagining of the hit 1980s TV show starring Lee Majors as a Hollywood stunt performer who moonlights as a bounty hunter, the film is an invigorating combination of action, suspense, and romance, as stuntman Colt Seavers (Ryan Gosling) must track down the missing movie star he's doubling for while contending with an old flame, the film's director Jody Moreno (Emily Blunt) — and their still-crackling chemistry.

For director Leitch and producer McCormick, the premise hit close to home. A former stuntman who's doubled for Brad Pitt and defied gravity in "The Matrix," Leitch is deeply familiar with the world of stunt performing, not to mention workplace relationships in Hollywood: He and McCormick met around 2011 when she became his manager helping him move from the world of stunt coordinating to directing.

"It's honestly very refreshing," Leitch told Business Insider alongside his wife, "to be able to direct something from such a place of —" he paused to find the right word, but McCormack beat him to it: "Connection."

Below, Leitch and McCormick discuss how their relationship inspired Gosling and Blunt's on-screen chemistry, why a Kiss song became the glue of the movie, and why deepfakes are scary in the wrong hands.

'The Fall Guy' evolved from film noir to action rom-com

"The Fall Guy" movie adaptation had been bouncing around Hollywood for decades, with everyone from Nicolas Cage to Dwayne "The Rock" Johnson attached to star. When it finally got into McCormick's hands a few years ago, she knew instantly it would be perfect for her husband.

"I saw it as a legacy title for David with his stunt background," she said.

The duo thought they had the perfect angle: making it a noir. With Ryan Gosling already interested in playing the lead, the three pitched it to Universal, who loved the trio together for the IP but weren't into the film noir part.

"We got back notes that it needed a little bit more," McCormick said. "It wasn't very funny and we all leaned toward making it more fun and bigger and more commercial."

Suddenly, the movie became an action rom-com, something that solidified once Blunt signed on to play Jody, Colt's old flame. "Once Emily came on board, the love story grew and became a key plot point," Leitch said.

From there, the fun began, with Leitch and McCormick plugging elements of themselves and their story as a couple into the characters. "A lot of the truth is stranger than fiction; people have romances on sets and fall in love," Leitch said.

Gosling and Blunt took it from there, marking up the script daily with new ideas and tweaks, which often led to memorable moments that made it into the final cut.

"I remember the opening oner, where Colt does the free fall stunt, the 'imagine that' line that Ryan and Emily say back and forth to each other — we came up with that line that morning," McCormick said. "That 'imagine that' line turned out to be a callback to the characters through the movie, but that was a last-second addition."

No one wanted the Kiss song "I Was Made for Lovin' You" in the movie — except Leitch

David Leitch movies are known for combining action sequences with perfectly placed needle drops — so much so that Leitch said he usually writes the songs he wants to be featured into the script.

For "The Fall Guy," he was intent on using the hit 1979 Kiss track "'I Was Made for Lovin' You" in a key scene. Including the song became Leitch's obsession: He even wanted Colt and Jody to wear Kiss tour shirts as an indicator of having the same taste, and he wanted the song featured throughout the movie.

The problem? No one was into his idea.

"I rejected that right away," McCormick said. "And then Ryan was like, 'Yeah, that doesn't really feel like us.' And then Emily rejected it. So Kiss started to disappear from the project. But then, when David was in post, no other song worked but 'I Was Made for Lovin' You.' It was so funny because David, honestly, manipulated all of us the whole time."

Leitch noted that he did try other songs for the scene before finally going back to his original idea. He even went as far as rerecording the track with the UK singer Yungblud, making a ballad version and an orchestra version, all of which are featured in the movie along with the original Kiss track.

McCormick still can't believe he pulled it off.

"I'm also his wife, so I was like, is your manipulation that deep that though we all said no, it's literally the only thing that works? How is that possible?"

"I was a little creeped out," she jokingly added.

The movie's use of deepfakes highlights the dangers of powerful technology in the wrong hands

Last summer, Tom Cruise's nemesis in "Mission: Impossible — Dead Reckoning" was AI. This summer, Ryan Gosling goes up against deepfakes.

In "The Fall Guy," Gosling's Colt must clear his name after footage appears to implicate him in the death of another stuntman. In reality, it wasn't him — the villain digitally manipulated the footage of the culprit, placing Colt's head on their body. This is known as a deepfake.

Leitch and McCormick said they didn't want this plot twist to be heavy-handed, but they did want to highlight the dangers of powerful technology when it's placed in the wrong hands.

"We don't want to be scared of it," McCormick said, noting that it's common practice for Hollywood to use CGI to de-age and otherwise digitally manipulate its stars' likenesses.

"When people are taking the image and using it without consent is when it gets scary," Leitch added. "And that's where we need to regulate. That's what everyone is worried about."

The Taylor Swift song "All Too Well" wasn't originally in the movie

When Colt is at a low point in the movie, he jumps in a car and blasts the Taylor Swift song "All Too Well." But it turns out that wasn't the song Gosling was listening to while filming the scene.

"On the night we were playing Harry Nilsson's 'I Can't Live If Living Is Without You' as the mood music," Leitch said.

It wasn't until post-production that McCormick suggested trying Swift's most epic breakup anthem for the scene.

"The Harry song felt a little too over the top," she said. "Taylor's was just perfect. It's hard to put her music in a movie because her songs are a story, then you're telling a story on top of that. That's hard to do. But it's so evocative; it was the perfect vibe, nothing else fit once we tried it."

"The Fall Guy" is in theaters now.