LOS ANGELES — It Ends With Us actor and director Justin Baldoni has sued his co-star Blake Lively and her husband, Deadpool actor Ryan Reynolds, for defamation on Thursday in the latest step in a bitter legal battle surrounding the dark romantic drama.

The lawsuit from Baldoni and production company Wayfarer Studios, which also names publicist Leslie Sloane as a defendant, comes about two weeks after Lively sued Baldoni and several others tied to the film, alleging harassment and a coordinated campaign to attack her reputation for coming forward about her treatment on the set.