During Charli XCX‘s sold-out show at Madison Square Garden on Monday night, Lorde made a surprise appearance alongside the pop superstar. The dynamic duo performed their “Girl, so confusing” remix live on stage together for the very first time, strutting the stage in lockstep with each other while the crowd went crazy. The MSG show is part of Charli’s wildly successful co-headlining Sweat Tour with Troye Sivan, which is in support of her recent cultural phenomenon record, Brat. The high energy performance also featured another special guest, Addison Rae, who delivered the live debut of her new single, “Diet Pepsi,” and Rae, Charli, and Troye all performed the “Von Dutch” remix together. Charli and Troye’s Sweat Tour hits Philadelphia on Wednesday (September 25), before heading to Baltimore, Boston, and Chicago over the upcoming week. (Rolling Stone)