Justin Baldoni is taking legal action against his "It Ends With Us" co-star and her husband in a lawsuit he filed on Thursday.

Baldoni, in a lawsuit filed in New York federal court on Thursday, alleges extortion, defamation and claims related to breach of contract, among several others. He’s joined by his film studio, Wayfarer, and its chief executive Jamey Heath, and their public relations representatives, Melissa Nathan and Jennifer Abel. They seek at least $400 million.

The legal battle offers a glimpse of the feud between the co-stars of a box-office hit.

LOS ANGELES (AP) — “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 and extortion on Thursday in the latest move in a bitter legal battle surrounding the dark romantic drama.

It’s common knowledge that Blake Lively and Taylor Swift are very good friends. Now, reports are coming out left and right that Justin Baldoni referenced the “Fortnight” singer in his lawsuit against Lively and Ryan Reynolds.

Justin Baldoni filed a federal lawsuit against his "It Ends With Us" co-star Blake Lively, her husband Ryan Reynolds and others on Thursday.

Justin Baldoni mentioned Taylor Swift in his heated legal battle with "It Ends With Us" co-star Blake Lively. The actor claimed Lively pressured him using Swift's friendship.

Blake Lively has accused Justin Baldoni of employing manipulative tactics in his $400 million lawsuit against her and Ryan Reynolds.

Taylor Swift is reportedly “confused” about getting named into Baldoni's suit because her “connection to Blake” is one of “friendship.”

The popstar and her parents dined out in downtown Manhattan Friday, one day after she was named in Justin Baldoni’s $400 million lawsuit against Blake Lively and Ryan Reynolds.

From Wendy Williams speaking out against her conservatorship, to Justin Baldoni suing Blake Lively for $400M, in this edition of The Chat with Kam, FOX 29’s Kamryn Scrivens breaks it all down.