At first, Your Sister's Sister plays like a comedy of very modern manners, everything so up to date that antique notions of "good" and "bad" can be replaced safely by "gratifying" and "weird." Jack (a bearish Mark Duplass) is a sweet, modern guy, but he's sad, because his brother died a year ago. So Iris (Emily Blunt), Jack's friend and his brother's ex, sends him to her family's cabin for a little alone time. But the cabin is already occupied by Hannah (Rosemarie DeWitt), Iris's lesbian sister, who's there to get over a failed relationship. Jack and Hannah indulge in a drunken hookup, only to awake and find Iris paying a visit. After that, things get complicated - they even venture a little past manners and into morals. When someone says, "I'm a very bad person" here, it's an entirely sincere statement. Director Lynn Shelton's best trick is providing a picturesque space for some very fine performances; it's a real pleasure to watch the angular DeWitt and the cherubic Blunt conjure the shared history of siblings. (2011) — Matthew Lickona