Taylor Swift joins HAIM onstage for a surprise performance during their concert at London’s O2 Arena. See behind-the-scenes moments from the “Love Story” singer! Full Story: https://www.eonline.com/news/1339032/taylor-swift-joins-haim-for-a-surprise-performance-and-its-the-love-story-we-always-needed #TaylorSwift #HAIM #ENews Subscribe: http://bit.ly/enewssub About E! News: The E! News team brings you the latest breaking entertainment, fashion and Pop Culture news. Featuring exclusive segments, celebrity highlights,