Sebastián Silva’s slippery black comedy begins something like a cross between Curb Your Enthusiasm and Girls. Silva plays a version of himself, a film director called Sebastián Silva living in Mexico City; he’s meant to be working, but instead he idles days away on the sofa in his flat morosely snorting ketamine, Googling his own name and researching suicide methods. It’s a deeply unflattering portrait of entitled privilege from Silva and co-writer Pedro Peirano. Sebastián is mean to his dog and unforgivably rude to his housekeeper Vero (played by brilliant Catalina Saavedra, star of Silva’s film The Maid). Keep an eye on Vero, she will be important later.

To escape his funk, Sebastián takes a trip to the coast – staying at a gay partying spot heaving with hot naked men. Silva packs in more penises in five minutes on the beach than I’ve seen on cinema screens in a decade of movie-watching; his representation of hedonistic gay culture feels nicely casual and natural. On the trip, Sebastián meets an influencer called Jordan Firstman, famous for his TikTok impressions (impressively played by real-life comedian Jordan Firstman). Jordan is obnoxious, pushy and self-obsessed, but he’s no airhead. Savvily, he pitches Sebastián a TV project and arranges to meet him in Mexico City.

Then something terrible happens. To say any more would ruin the absolute jawdrop-woah! pleasure of the moment. And it’s here that the film wriggles out of its satirical skin – and loses the plot somewhat – as it becomes more like a successor to Agatha Christie, with echoes of modern mysteries Knives Out or The White Lotus, though this arthouse whodunnit is slightly less satisfying. Perhaps that makes it closer to life – with a hopelessly inept amateur investigation, followed by a denouement involving a phone translation app failing big time.

• Rotting in the Sun is released on 15 September on Mubi.