The "Fifty Shades of Grey" flick has cast another sultry star: Rita Ora.

The 23-year-old singer will play the adopted sister of Christian Grey in the film adaptation of E.L. James' erotica novel, starring Jamie Dornan as Christian.

"It's official!" Ora tweeted. "I've been cast in @FiftyShades of Grey as Christian's sister Mia."

The movie is slated for a Feb. 13, 2015 release.