Is mumblecore dead? Jay and Mark Duplass, who helped pioneer the genre characterized by low action and extensive navel-gazing, have certainly taken a step away from it in Cyrus, a love-triangle comedy in which two of the parties are mother and son. Yes, it’s a sitcom setup. Or maybe a pornographic one. Yet the Duplass brothers, who also wrote the script, hold back just when you expect things to go over the top.

This restraint may leave you disappointed at first, but ultimately it’s impressive—and it makes you consider that, just maybe, you spend too much time in front of screens big and small. It’s difficult to critique the film without giving too much away, but the plot involves John (John C. Reilly), a sad-sack divorcé whom we meet in his dingy apartment as his ex, Jamie (Catherine Keener), catches him tending to his “jock itch.” She’s there to tell him that she’s getting remarried. Though she’s been dating the man for years, John’s taken aback. “It still stings,” he says. “It’s still a surprise.”

For no known reason, John agrees to go with the couple to a party. Naturally, he has a lousy time, alternately keeping to himself, getting loaded, treating strangers as therapists, and trying to ignore Jamie’s condescending fiancé. (“There are a lot of pretty girls here, John!”) Then he goes outside to pee in the bushes and—expediently—meets a dream: Molly (Marisa Tomei), who overheard his poor-me monologues, thinks he’s “raw and honest.” John is thrilled but then suspicious. “I’m, like, Shrek,” he says, “What are you doing in the forest with Shrek?”

Molly likes Shrek just fine, though, and soon he’s proclaiming her a “sex angel.” They see each other often, but she repeatedly refuses to spend the night, saying, “My life is complicated right now.” So, one night he follows her home, and while doing some closer surveillance the next day, gets spotted by Molly’s son, Cyrus (Jonah Hill). As they wait for Molly to come hoe, Cyrus entertains the interloper by playing his self-composed, trancey music (one of the film’s funniest scenes), then asks if he’ll stay for dinner. On her arrival, Molly’s surprised, but doesn’t ask any questions right away.

Such illogic continues as the plot expands. Molly’s kid acts as if he’s level-headed and welcoming until he doesn’t; Molly assures John that he’s important to her, yet defends her son and their habits, such as leaving bedroom doors open or wrestling as though Cyrus were a toddler. John is polite, for only so long, eventually confronting Molly and Cyrus about their weirdly close relationship. Answers—at least plausible ones—are scant.

Even though there’s a lot more plot, and life, to Cyrus, it still bears a few precious hallmarks of a Duplass brothers’ film. It takes only seconds for their camera to start wavering and zooming abruptly in and out, to no thematic effect. There’s a scene in which conversation is heard in voiceover as we watch the couple apparently addressing each other, but their mouths don’t move. And awkwardness abounds: John interrupts Molly’s flirtation with him at the party to run inside and drunkenly warble “Don’t You Want Me,” as others gawk with obvious pity. He stalks her. And during a first dinner, Cyrus tells John, “Don’t fuck my mom.”

This last is amended with “That’s my attempt at humor, John,” but you’re not sure whether it’s a joke or not. Some more certain laughs counter the creepiness, thanks to Reilly and Hill’s improv (also typical of the filmmakers’ work). Reilly’s charm sometimes makes it hard to believe John’s such a loser, but when he calls Cyrus “a little weirdo,” there’s both levity and bite. And Cyrus can be as funny as Hill’s broad Apatow-ian characters, as when he stares straight-faced at John while playing his music or describes John’s hair, with a childlike grin, as looking like “a crippled tree reaching for heaven.” Mumblecore may have been hailed as refreshing realism, but here the kings of it prove that a more mainstream approach can likewise balance comedy and seriousness, structure and looseness, and generally move the way life does without annoying audiences to distraction.