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But Calvin soon responded on social media site Twitter, revealing fans would never hear his side of the story.
Rita Ora and Calvin Harris
Talking to Ryan Seacrest live on air, Rita said: "Unfortunately we couldn't do the Teen Choice Awards", before adding: "Ask Calvin!" when asked by Ryan she did not end up performing.
"[Calvin's] an incredible song writer and I'm never going to disregard his talents. He has to approve anything TV-wise, for anybody who doesn't get it. And obviously he owns the rights to it and he didn't approve of the Teen Choice Awards", Rita continued.
She added: "I was scheduled to perform... We put a lot of effort and work into the show.
"I could have got told a few weeks earlier. That would have been nice."
You'll only know 1 side of the story RE Teen choice awards because I choose not to talk to the papers about every aspect of my personal life— Calvin Harris (@CalvinHarris) August 13, 2014
But just know I had a damn good reason— Calvin Harris (@CalvinHarris) August 13, 2014
The 30-year-old DJ later responded on Twitter, tweeting: "You'll only know 1 side of the story RE Teen choice awards because I choose not to talk to the papers about every aspect of my personal life.
"But just know I had a damn good reason."
Summer singer Calvin, 30, put an end to rumours that he and Rita, 23, had gone their separate ways on Twitter earlier this year.
He tweeted: "To address speculation - myself and Rita ended our relationship some time ago," he wrote. "She is a beautiful, talented woman and I wish her all the best."
Rita Ora live on Ryan Seacrest's radio show
It was thought that the pair had split amicably.
Last week, Rita, 23, revealed that although she isn’t struggling as much as she predicted since they parted ways, her situation "sucks".
"I'm gonna tell you the truth, I'm not doing too great," she told Glamour magazine. "But, I'm doing better than I thought. I adore him and he's such an amazing human being. It was more about the situation, it was inconvenient, it sucks. It wasn't about 'us' it was about the world we live in."