Charli XCX joined Taylor Swift on stage to perform her hit single “Boom Clap” wearing the Charli Leopard Glitter Cut Neck Top ($20.00), mustard yellow Charli Faux Fur Detachable Cuffs ($14.00), and the Charli Leopard Sparkle Pant Trouser ($26.00) — all from her collaboration collection with Boohoo — with a pair of vintage shoes similar to the Pleaser Candy-09 Platform Sandal ($22.42+).