It’s a time-honored trope in both horror and comedy: a longtime couple is about to get married, but the major hitch before the actual hitching is that one of the parties in question has to meet the other’s family first. And of course, said family turns out to be insane; either hijinks or a body count (or sometimes both) ensues.

Trash Fire, which was the opening night feature of this year’s Screamfest in Los Angeles, takes the formula down a more darkly humorous path than normal. Our lead couple, Owen (Adrian Grenier) and Isabel (Angela Trimbur) are far from an ideal pair. She wants a family, and has self-admitted low self-esteem, while he’s casually horrible to her, at one point offering to split the cost of an abortion 50/50 right after she’s confessed her anxieties about never being a mom. She’s from a Christian family; he feigns Satanism to piss them off. He’s also bulimic and alcoholic, with a therapist who falls asleep during their sessions. But right when Isabel has finally had enough and prepares to kick him out, he has a seizure which prompts both his life to be momentarily endangered, and the movie screen to suddenly blast us with feedback noise and quick cuts of Isabel covered in blood in a burning house.

He eventually recovers and they have terrible, awkward sex of the sort you’ve probably experienced at least once but never actually seen depicted in a movie so honestly (Grenier is not afraid of butt shots, nor of looking like he’s a lousy lay). Both partners are convinced they’re sterile; at least one of them is wrong. And when Owen finally presents himself as even semi-willing to be a dad, Isabel insists he prove he cares about family by trying to patch things up with his own. This, he insists, is a really bad idea, and she does not know what she’s asking. And since you’re reading a review of this movie based on it’s having played a festival called Screamfest, you might have gathered that what’s coming is going to be an order of magnitude worse than Robert De Niro in Meet the Parents.

Writer-director Richard Bates Jr. has mined similar territory before with Suburban Gothic, though he has improved immensely since then. While both features deal with a young man going home to face near-literal demons from his childhood, Gothic tried to embrace a John Watersy level of kitsch, prioritizing style over substance. Trash Fire is lit and colored like a David Fincher film, lending literal and narrative darkness to the early comic scenes. Where most horror movies of this sort would have the “normal” relative somehow defending his weirdo killer clan, Owen feels more like the real-life natural outcome of an upbringing with nutcases. He’s a total a-hole by any stretch of the modern urban dating imagination, but compared to the rest of his family tree, he’s a saint. All his neuroses and mean wisecracks are simply coping mechanisms. In an amusing mixed-message kind of a way, Isabel grows closer to him once she sees that hey, he could have been way worse.

Bates seems to me to be fighting his natural instincts a bit, as the early, non-horror parts of the movie are the best, with Owen brutally putting down Isabel’s pious brother, and generally being the boyfriend from…not quite hell, but certainly purgatory. Once they drive upstate, Fionnula Flanagan does have several scene-stealing bits as the tart-tongued grandmother of your nightmares, and AnnaLynne McCord radiates innocence and menace as Owen’s scarred and pervy sister. However, the tension and give-and-take between Owen and Isabel—the best part of the movie—disappears once they’re forced to work together.

Without spoiling specifics, Bates also seems to prefer fakeouts and sudden surprises to consistently building tension toward a climax; that said, his dialogue is fantastic throughout, and his actors deliver it perfectly, give or take a handful of extras playing televangelists. I’d like to see an all-out proper rom-com from him down the road.

Rating: 3.5 out of 5.

Image: Orion Pictures

Luke Y. Thompson is Nerdist’s weekend editor, and looks forward to Screamfest every year. Following him on Twitter is also allegedly a scream.