Two sisters, two boyfriends, one simple birthday weekend getaway. Or it would have been, if not for the threesome, the affair, the unexpected arrival of a fiancé, and the ensuing ridiculous dinner role play charade everyone is forced to participate in just to keep from getting caught. Monogamy doesn’t run strong in Claire and Ali’s family. But there’s a healthy way of dealing with the desire for more than one partner — for instance, Ali and her boyfriend Art are inviting Jas, a woman they met on a polyamory app, to join them for a threesome — and a not-so-healthy way — like how Claire is cheating on her fiancé, Zach, with her co-worker, a guy named, in all seriousness, String. When all six of these people find themselves stuck in the same house for what was supposed to be a beach weekend, the result is something of a dramatic farce: intensely felt, emotionally raw, and laugh-out-loud funny.