Taylor Swift Turns Up the Heat With Nelly and Haim

Things got hot, hot, hot when Taylor Swift welcomed her latest guests to the stage during her tour stop in St. Louis on Tuesday. The singer was joined by Nelly and a few of her BFFs, Haim's Este, Danielle, and Alana Haim. Together, the whole group performed Nelly's "Hot in Herre," and his new single, "The Fix," and as Taylor explained on Instagram, she and her friends made up a dance together in the dressing room. She also shared a picture of herself singing alongside Nelly, writing, "Old friends. @derrtymo has come out to surprise the crowd on my last 3 tours. I absolutely adore him." Keep reading for all the best pictures from the group's performance, and then check out all the guests she's welcomed to the stage throughout the 1989 tour.