Lynn Shelton’s breakthrough film Humpday was an improv workshop turned magic act. Give two actors, Mark Duplass and Joshua Leonard, an almost impossible premise — two straight male friends decide to make a gay porn together — and watch them turn it into something plausible and heartfelt. The acting and ostentatiously hand-held camerawork were on the shambling side of naturalistic, but the foot-dragging was balanced out by the audacity of the organizing principle, the voice in the back of your head that kept murmuring, “I can’t believe this is working.” Unfortunately, with Shelton’s new film, Your Sister’s Sister, that voice is replaced by one saying, “Really?”
Duplass returns, sandwiched in between sisters Emily Blunt and Rosemarie DeWitt. He is, a year later, still shell-shocked by his brother’s death, as Blunt is by the loss of her former boyfriend, while DeWitt has just ended a seven-year relationship with another woman. The three converge, via a combination of subterfuge and coincidence, on an island off the coast of Seattle. DeWitt and Duplass, who’ve never met, arrive first, and after a night of increasingly drunken banter, he unseriously propositions her and she abruptly accepts. Blunt arrives the next morning without advance notice, and complications, as they will, ensue. It sounds like the stuff of farce, or its inbred, nth-generation offspring, the sitcom. Regardless, it’s not something actors should have to approach with a straight face, let alone one limned with such all-fired solemnity.
The movie is most alive when nothing is happening, when Duplass and DeWitt are sitting around a varnished wood table slugging tequila shots or DeWitt complains that the nonvegan mashed potatoes she’s been duped into eating contain “five pounds of fear.” But the more Shelton pushes her characters into familiar territory, and especially as she strong-arms a trumped-up denouement, the more the actors’ realism starts to feel like the worst fraud of all.