Article continues below advertisementTaylor Swift and Charli XCX Posed for a Photo at a 2014 EventSource: MEGATaylor Swift and Charli XCX have sparked feud rumors.Do Taylor Swift and Charli XCX have bad blood now?Long before they sparked feud rumors, the two pop stars posed for a photo at iHeart Radio's Jingle Ball concert in December 2014.Article continues below advertisementCharli XCX Sang Taylor Swift's Hit Song 'Shake It Off' and Served as a Special Guest on the 1989 World TourSource: MEGACharli XCX performed the track a few months after they met at the New York event.