Taylor Swift is allegedly upset that American television personality/model Kendall Jenner and One Direction star Harry Styles have reunited. The Bad Blood hitmaker, who is dating Scottish singer/DJ Calvin Harris, apparently cannot accept the British singer being with anyone else.

"Taylor hates to hear about Harry being with anyone else. It's not that she's still in love with him or anything, but her whole relationship with him was kind of a blow to her ego. He had such a wandering eye and he was such a flirt that she was always on edge. Plus, he always made it clear that he loved exotic women with dark hair and dark eyes, so the fact that he's dating Kendall Jenner hasn't exactly made her feel awesome," a source told Hollywood Life.

It was previously revealed that the Red singer was single for a long time since splitting up with Styles. Swift, who has a history of dating high-profile celebrities including Jake Gyllenhaal, Joe Jonas, Taylor Lautner, John Mayer, Zac Efron and Conor Kennedy, split with Styles in January 2014, after dating for two months.

"Taylor is not catty and she wishes them well, but she's human and seeing him move on kind of bites," the insider added.

Meanwhile, during an interview with NME magazine, Swift said she feels the world is too interested in her personal life. She told the publication: "I'm in the news every single day for multiple different reasons. And it can feel, at times, if you let your anxiety get the better of you, like everybody's waiting for you to really mess up – and then you'll be done."

"A lot of the time I need to call my mom and talk for a really long time, just to remind myself of all the things that are great and all the things that matter. If you do something that defines your character to be not what the public thought you were, that's the biggest risk."