Cheryl brands Cher "unappreciative", Example questions Alexandra Burke's real age and Kanye West offers Taylor Swift a grovelling apology. We round up the biggest spats in pop star history.
Rita Ora and Calvin Harris fell out on Twitter after Rita gave an interview which suggested she had turned down Calvin's song 'Call My Name', which was recently released by Cheryl Cole. Her comments prompted Calvin to tweet: "For the record, Call my name was never given to Rita Ora to sing... she made that up, don't know why." Rita then tweeted that the media had twisted her words and that she hadn't said she turned the track down. After realising it was a misunderstanding, the pair resolved their differences, with Calvin tweeting: "thank you luv + good luck with everything!"