This is undoubtedly one of the most insightful films ever made about friendship between straight males. Though it has a rather high concept hook, Humpday is far from gimmicky, instead opting to explore its characters’ relationships in a loose, naturalistic way. Director Lynn Shelton – whose latest film, Your Sister’s Sister, also explores unusual dynamics of friendship and sex – crafts a coherent, thoughtful and very funny film out of directed improvisations centering around a doozy of a “will they or won’t they” proposition.

Humpday is endearingly honest right from the start, as it opens with a scene that should be familiar to anyone who’s ever been in a long-term relationship, especially one that involves living with a partner. Ben (Mark Duplass) and his wife, Anna (Alycia Delmore), lie in bed together, each half-heartedly trying to initiate sex before they both admit, with a sense of relief, that they’re too tired. They are awakened a few hours later by the late-night arrival of Ben’s old college buddy, Andrew (Joshua Leonard, best known as “Joshua Leonard” in The Blair Witch Project), who has continued to live the freewheeling life he and Ben shared in their college days. As the two rekindle their friendship, they discover that each has a certain degree of envy for the other’s life, despite the fact that they wouldn’t actually want to trade places.

Things get more complicated on the second night of Andrew’s stay, when he hooks up with an artist named Monica (Shelton) and invites Ben to have dinner and drinks at her anarchistic, communal home, known as “Dionysus.” It is here that Ben learns of the HUMP! festival, a real-life amateur porn fest that takes place annually in Seattle. As explained by the bohemian artists at Dionysus, it’s more about artistic expression than pornography, and Ben and Andrew joke about the idea of shooting a scene together, despite the fact that they are both straight. In their eyes, this would somehow be a truly unique artistic statement, while also providing an intense and unusual bonding experience for them as friends. When they discuss the idea again in the sober light of day, it becomes a challenge from which neither of them wants to back down; Ben wants to prove he’s not as domesticated as he seems, and Andrew wants to live up to the free spirit Ben believes him to be.

It is fitting that this misbegotten plan begins as a somewhat testosterone-fueled dare, the modern adult male equivalent of sorority sisters being encouraged to make out despite having no real attraction to one another. The eventual porn shoot attempt is brilliantly conceived and executed, a realistic and hilariously awkward sequence that perfectly encapsulates not only the truth of platonic male friendship pushed to its limits, but also the bittersweet revelation that the golden age of that friendship has passed, leaving only fond and funny memories.

Hidden Netflix Gems is a new feature designed to help readers answer that burning question, “What should I watch tonight?” It will be updated every Saturday before the sun goes down.