A low-key indie dramedy which was shot in just 12 days, Your Sister’s Sister is somewhat slight and familiar, but it still manages to offer some reasonably insightful material on love and sibling relationships. Very much a three-hander, it sees a self-aware slacker (Mark Duplass), his best gal-pal (Emily Blunt) and her lesbian sister (Rosemarie DeWitt) all end up in the same island cabin together for the weekend, with little more than tequila and overdue revelations to keep them company. Naturally, complications ensue.
With large parts of the dialogue improvised, the conversations and interplay feels noticeably naturalistic (or, perhaps that should be, un-noticeably naturalistic?), while writer-director Lynn Shelton throws in a few plot twists to occasionally heighten the drama. Sadly though, while the movie finishes perfectly by cutting at exactly the right moment, the final act is tarnished when an unforgivable act (which involves one of the trio piercing holes in something as part of their agenda) is forgiven in a way which is more sentimental than it is satisfying.