When Kyle Marvin made his first movie, he made one big mistake. “I gave up my day job way before I should have,” he says with a laugh.

At the time, Marvin, 40, was working in advertising with his best friend, actor and director Michael Angelo Covino. They shot sketches, produced the occasional project and eventually decided to write, produce and star in their own short film, The Climb, about a friendship tested during a weekend bike ride. “My wife and I had a good life, we were raising two children, and I was like, ‘I’m going to give it all up and go make movies,’ ” Marvin recalls. ” ‘And I’m going to make absolutely nothing — in fact, I’m going to lose money.’ I sold our family car to finance the movie.”

The Climb premiered at Sundance in 2018 and was so well received that it was expanded into a feature, which premiered at Cannes in 2019 and went on to play Telluride and Toronto that same year. Now, half a decade later, Marvin is reteaming with Covino, co-writing, co-producing and co-starring in Splitsville (in theaters Aug. 20), a relationship comedy with studio muscle from Neon and extra star power from Adria Arjona and Dakota Johnson. “I have more stability now, obviously, but I still have that same ‘fuck it’ mentality,” he says. “Where it feels like you’re taking your clothes off, jumping into a pond and you might drown.”

In this case, the metaphor isn’t far off — Marvin has more than a few nude scenes in Splitsville. It opens with his character and his wife (Arjona) on a drive to a couples weekend with their best friends (Covino and Johnson) that turns out to be filled with bombshell revelations, starting with his wife’s confession that she’s been unfaithful and wants a divorce. Once they arrive, the confessions keep coming — including that their friends are in an open marriage. The chaos spirals into sexual entanglements, absurd confessions and an extended slapstick brawl that sends Marvin and Covino crashing through windows, tumbling over furniture and getting Marvin’s eyebrows singed off in a hairspray-and-lighter stunt gone wrong.

“We really, genuinely beat the shit out of ourselves filming that, and we shot it before I had to go and do the nude scenes,” he says. “The makeup team would take my clothes off and just be like: ‘What?!’ They were airbrushing bruises and cuts off of me.”

Marvin with Adria Arjona in Splitsville.

Neon/Courtesy Everett Collection

The premise, Marvin insists, comes not from his own marriage (he’s been with his wife for 20 years, and they now have three kids) but from conversations — some overheard — as he and Covino searched for a lean, spicy concept that could be shot quickly and economically. “Everybody in my life has said that I stole a piece of their story for this movie,” Marvin says. “This movie isn’t only about open marriages or cheating — which is what they used to call open marriages — it’s about how we’re all challenged in our relationships. The movie is just trying to unpack all that in a fun setting.”

Since The Climb, Marvin also has built a parallel, more commercial career: portraying WeWork co-founder Miguel McKelvey in Apple TV+’s WeCrashed, directing Paramount’s 80 for Brady and prepping a biopic about mountain climber Warren “Batso” Harding. He says that trajectory wasn’t plotted out in advance — not even when he quit his job and sold his car — but rather came from taking small steps toward what he wanted and proving himself along the way.

As for what’s next, Marvin’s hoping Splitsville‘s momentum will help him keep climbing. “It feels like bullshit when I say it out loud, but I really do just want to make things that reach a lot of people and yet still have that tone and potency I’m always chasing.”

Marvin with Jared Leto (left) in WeCrashed.

Peter Kramer/©Apple TV+/Courtesy Everett Collection

This story appeared in the Aug. 13 issue of The Hollywood Reporter magazine. Click here to subscribe.