The "Bad Blood" singer shared an Instagram photo of the two, joined by model Gigi Hadid, Joe Jonas, and Taylor's BFF Karlie Kloss.
She captioned the pic, "Little known fact: Karlie is secretly an unofficial historian/London tour guide. Kind of."
Taylor performed in front of a crowd of 65,000 on Saturday night in Hyde Park as part of her “1989” world tour. The 25-year-old singer brought Hadid and Kloss onstage, along with “Keeping up with the Kardashians” reality TV star and model Kendall Jenner, tennis great Serena Williams, and “Paper Towns” actress Cara Delevingne.