When not working alongside brother Jay to co-write and direct such films as Cyrus and last year’s Jeff, Who Lives At Home, Mark Duplass likes to stay gainfully employed by acting in other people’s movies and TV shows. His latest gig is in Melissa McCarthy’s new comedy Tammy.

The Identity Thief actress co-wrote the comedy with her husband, Ben Falcone. And, following the departure of original director Beth McCarthy-Miller, the pair has stepped up to call the shots together on the film.

McCarthy will star as a woman who loses her job and discovers her husband is a big lying cheat on the same day. To get away from her life problems, she hits the road with her foul-mouthed, booze-guzzling grandmother (Shirley MacLaine was in talks, but she apparently didn't make a deal). According to the Hollywood Reporter, which updated the MacLaine siuation, Susan Sarandon is in talks to play granny's lesbian friend, who steps in to save the pair in some difficult moments.

Along the way, McCarthy meets a man (Duplass) and they develop a strange relationship. It’s just the latest job for the busy multi-hyphenate, who was last seen on screen in Zero Dark Thirty. He’s most recently worked on JFK assassination drama Parkland, low-budget comedy horror Peachfuzz and far darker horror thriller Mercy. As for his directing/producing career, he and his brother are due to kick off work shortly on their HBO comedy Togetherness, which follows two couples trying to live together under one roof.