A buddy comedy that gets laughs from ideas, Humpday is exceptional in its naturalness, strong performances and—in spite of its seemingly impossible premise—believability. Suburban husband Ben (Mark Duplass) is confronted with his college-age hipster-self in the form of his old buddy Andrew (Joshua Leonard). When they reunite, Andrew rubs his vagabond-artist life in Ben’s face until, somehow, they challenge each other to make a porn film. Starring themselves. And no one else. The two straight guys deal with their refusal to back down from their ridiculous dare with rationalization, self-doubt and unusually honest investigations of their own psyches, until a silly comedic premise becomes an uncomfortable and hilarious exploration of midlife. The breakout performance is by Alycia Delmore as Ben’s wife, Alice. Her reactions shots are worth twice the price of admission, and director Lynn Shelton’s intimate filming style and strong sense of place and character make this one of the most interesting films of the last six years.