This one is less of a feud and more of a story of possibly bitter exes. At the 2013 VMAs, Taylor (yet again!) ran into one of her exes, Harry Styles of One Direction. The pair dated for an extremely short time in 2012 and into 2013, but Harry apparently provided Taylor with plenty of material for her album Red.
In 2013, Taylor won best female video for "I Knew You Were Trouble," seemingly about Harry, and when she took the stage to accept her award, she gave a shady shout-out to Harry himself. "I also want to thank the person who inspired this song because he knows exactly who he is."
But wait, it gets better! When Harry was on stage with One Direction during the show, the camera panned to Taylor, who was chatting with pal Selena Gomez beside her, while Harry was talking, and it kiiiinda looked like Taylor said, "Shut the f*ck up," at Harry. Yikes.
The two mostly ignore each other these days, though Harry may or may not have a couple songs about Taylor under his belt now. (He totally does.)