The first trailer for Your Sister’s Sister has gone online.  The film stars Mark Duplass as a man still mourning his brother’s death who retreats to a cabin on Puget Sound at the behest of his best friend (Emily Blunt).  When he finds Blunt’s sister (Rosemarie Dewitt) at the cabin, the two sleep together after a tequila fueled night, only to wake up and find that Blunt has decided to join them at the cabin.  Though the premise could easily devolve into a by-the-numbers romantic comedy, director Lynn Shelton looks to have crafted a thoughtful drama that plays out the scenario in the most human, and realistic, of fashions.  I’m a big fan of the cast here, and Matt enjoyed the film at Sundance, so I’m looking forward to checking it out.Hit the jump to watch the trailer.  The film opens on June 15th.  If you missed them, you can also check out Steve's interviews with Duplass and Dewitt at Sundance.Click over to Yahoo! to watch in HD.Here’s the synopsis for Your Sister’s Sister:

A year after his brother's death, Jack is still emotionally fragile. When he makes a scene at a memorial party, Iris decides to intervene. She gets Jack to oil up his old bike and drive out to her father's cabin on an island on Puget Sound, where she hopes he will be able to work through things. When Jack arrives at the cabin, he does not find restorative solitude but instead Iris' sister Hannah, nursing a wounded heart and a bottle of tequila. After throwing back a few drinks, these two end up getting to know each other a little more intimately. Their hangover wake-up call arrives the next morning in the form of Iris with a bag of groceries in hand.