Rita Ora poses at the British Fashion Awards 2013. (Photo by Stuart C. Wilson/Getty Images)

E! Online – Safe to say this is the most surprising casting news of the day.

Rita Ora is set to play Christian Grey’s adopted sister Mia in the highly anticipated film adaptation of E.L. James’ erotic thriller, Fifty Shades of Grey. 

“It’s official! I’ve been cast in @FiftyShades of Grey as Christian’s sister Mia. #FiftyShades,” the British singer tweeted on Monday, Dec. 2.

The “How We Do” crooner will play the outgoing younger sibling of the BDSM-loving billionaire, played by Once a Upon a Time hottie Jamie Dornan, who was cast as the titular character after Sons of Anarchy star Charlie Hunnam exited the role.

Ora’s acting credits include a small cameo in Fast and the Furious 6, as well as a role in the British film Spivs

The 23-year-old singer-actress joins previously announced castmembers Dakota Johnson, who plays Grey’s love interest Anastasia Steele, as well as Eloise Mumford(Anastasia’s best friend Kate), Luke Grimes (Christian’s brother Elliot), Victor Rasuk(Anastasia’s close friend José), Jennifer Ehle (Anastasia’s mother Carla) and Max Martini (who was most recently cast as Christian Grey’s bodyguard).

Filming for the S&M-inspired flick commenced on Sunday, Dec. 1 in Vancouver, Canada, with author E.L. James sharing a behind-the-scenes glimpse on set.

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