Fifty Shades Of Grey hunk Jamie Dornan is set to embark on an affair with Girls star Jemima Kirke in new independent movie Untogether.

The Northern Irish actor, who recently completed production on the second and third blockbuster adaptations of E.L. James' erotic book series, has signed on for the dramatic comedy, in which he will portray a successful author, who falls for Jemima's character, a former teen prodigy and drug addict-turned-writer.

Jemima's sister, Gone Girl actress Lola Kirke, 25, will also be a part of the cast, marking the siblings' first movie together.

Bloodline's Ben Mendelsohn, 47, will play Lola's older boyfriend, according to The Hollywood Reporter.

Emma Forrest will make her feature-length directorial debut with Untogether, which she also wrote.

Filming is set to begin in October (16).

Meanwhile, Dornan recently made it clear he will not be back as Christian Grey if author E.L. James' fourth Fifty Shades of Grey book, Grey, is made into a movie.

"We have done two movies back to back now, and I'm actually finished with it," he told The Sun. "I've done Fifty Shades forever."