Sources exclusively reveal to In Touch magazine that Empire co-stars Taraji P. Henson and Terrence Howard have been clashing on set — and it’s causing major drama behind the scenes of the Fox hit.

“It’s gotten so bad that Taraji can’t be on set for more than 30 seconds without staring daggers at him,” a source tells In Touch of Taraji, who became close with the actor when they starred in 2005’s Hustle & Flow.

“She’s irritated by the pompous, bigheaded braggart that Terrence has become,” the source adds.

RELATED: Terrence Howard Opens Up About Seeing His Father Stab a Man to Death

taraji p. henson and terrence howard

“In the beginning, Taraji was the key supporter and apologist for his behavior,” says the source, noting that Taraji famously refused to take on the role of Cookie unless Terrence was cast as her on-screen love interest, Lucious. “But as his arrogance increased, she began to get annoyed.”

Empire’s producers secretly love their stars’ bitter feud, because it “prompts some amazing, volatile scenes between them,” adds the source. “The animosity is working to the show’s advantage.”

RELATED: ‘Empire’ Star Taraji P. Henson ‘Livid’ Over Season Two Pay Raise

Taraji’s rep insists that she and Terrence “are the best of friends and professional colleagues … always.”

For more on the cast of Empire, and all your favorite celebrities, pick up the latest issue of In Touch magazine, on newsstands now!

Have a tip? Send it to us! Email In Touch at contact@intouchweekly.com.