No one is ever ready for parenthood, regardless of how much they may want children. Maybe that’s why stories of happy-go-lucky, child-free men suddenly confronted with ensuring a child’s well-being—think About a Boy, or even the patently absurd Three Men and a Baby—often resonate. You can prepare for fatherhood, sure. But the unpredictability of kid behavior is always going to be the wild card.

That may be part of the allure of writer-director Jordan Firstman’s debut feature Club Kid, which became a surprise sensation at Cannes in May. Firstman, who’d started out as a comedy writer, first gained attention for some skits he’d posted on Instagram during the pandemic. But Club Kid came as a surprise. There’s something almost naively fresh about it, as if Firstman hadn’t stopped to consider that a plot like this one—a single gay man leaves the high life behind to care for the 10-year-old son he didn’t know he had—could invite some serious side-eye.

Somehow, Firstman makes the setup feel not only believable but moving. He stars as Peter, a party promoter who, with his coke-loving business partner Sophie (Cara Delevingne), pulls together events that draw New York’s freakiest, most fabulous, ready-to-rage crowds. Peter himself loves to partake of the drugs that flow so freely on the scene, and he sells them, too. Though he is, with absolute certainty, gay, it turns out there was one blurry night when he had sex with a woman. Ten years later—now in his 30s, Peter is still partying like it’s 2016—a woman he doesn’t know with a thick North London accent, Edison (Kirby Howell-Baptiste), shows up at his doorstep with a kid she says is his. Arlo (Reggie Absolom) is around 10, and his mother, Edison’s best friend, has recently died by suicide. So Edison brings Arlo to New York, passport and birth certificate in hand, and deposits him with Peter, who’s none too happy about this turn of events—and still a bit stunned that he ever did the deed that could result in an actual child.

Arlo has been through a lot, but he’s a bright, open-hearted kid with fantastic taste in music. Cocteau Twins are one of his favorites, and he’s got the cute, mid-1980s curly pompadour haircut to prove it. Peter can’t help liking Arlo, and tries to clean up his act when he realizes he wants to be a dad to him. He’s never really had to do grownup things, and their existential weight overwhelms him at first. Forget raising a child; he’s got to grow up himself, and fast.

Club Kid takes some surprising turns on the way to its delicately shaded ending. Firstman makes a believably clueless naif in dadworld, and he knows just what to do with a throwaway sight gag: slow-dawning horror crosses Peter’s face when he realizes he’s unwittingly given Arlo a T-shirt printed with an NSFW motto to wear as a nightshirt. Firstman has also peopled his film with charmingly eccentric second bananas, like leggy, ultra-glamorous Saffron (Saturn Risin9), a DJ who shows Arlo the ropes at the mixing board, and Nicky (Eldar Isgandarov), an elfin freeloader and aspiring philosopher who could probably carry his own spin-off.

But a movie featuring a child actor is only as good as the kid, and Absolom is quietly wonderful as Arlo. He never overplays, even when he’s retching in a bin after eating pizza. (Arlo hasn’t told Peter he’s allergic to dairy products.) At one point, Peter has to break up a fight between Arlo and another kid—it’s clear that Arlo is hiding some deep-rooted anger. We can see it passing through him like an electrical storm—and then it’s over. By the end, we see him as a real kid, not just an adorable prop in a movie that could have easily veered into sentimentality. Club Kid is, in the words of disco star Sylvester, mighty real.