Your Sister's Sister (2011) - Emily Blunt

Iris invites her friend Jack to stay at her family's island getaway after the death of his brother. At their remote cabin, Jack's drunken encounter with Hannah, Iris' sister, kicks off a revealing stretch of days.

 Director: Lynn Shelton
Writer: Lynn Shelton (screenplay)
Stars: Mark Duplass, Emily Blunt and Rosemarie DeWitt