"Fifty Shades of Grey" actress Rita Ora and Calvin Harris have split. Calvin Harris announced the news of their break up on Twitter, shocking Rita Ora. Was their split caused by Rita Ora's Instagram photos with R & B singer Khalil?

Calvin Harris wrote on Twitter a couple of week's ago: "To address speculation - myself and Rita ended our relationship some time ago. She is a beautiful, talented woman & I wish her all the best."

According to The Sun, a source said: "It was Calvin's decision to end the relationship. They had been arguing for months and had grown apart.

"Rita was left embarrassed when he tweeted that it was all over.

"She didn't think he was going to make the announcement, so she was shocked."

What caused Rita Ora, 23, and Calvin Harris', 30, break up? According to the Huffington Post UK, it looks like the Scottish DJ was not happy with Rita's Instagram posts, especially the ones with Khalil (like the one above).

"She was constantly posting snaps of her with other groups of friends and her trip to Mexico and photos of her with Khalil were the final straw," the source said. "Calvin likes more privacy than Rita and he hated the extra attention that came with being her boyfriend."

The "Fifty Shades of Grey" actress, who will play Christian Grey's sister in the movie, and Calvin Harris have been dating for some time, though they broke up for a few weeks in January.

"I don't usually address speculation but I've had an incredible time w Calvin,& i will treasure the memories," Ora tweeted Wednesday. "I've moved on from this topic so i hope people will respect that and do the same."

She added, "Life can only be understood backwards but it must be lived forwards."