The two dueted on “Boom Clap,” and Swift posted a video clip of the performance on Twitter.
XCX tweeted back her thanks and complemented Swift’s choice of wardrobe for her tour.
Swift welcomed Keith Urban on stage at her first Toronto show on Friday night. The singer’s ever-growing squad of celebrity guests (which already includes the likes of Nelly, Mick Jagger, Julia Roberts, and Matt LeBlanc) was also the subject of a sketch this weekend on the SNL season 41 premiere. With all the stars Swift keeps adding to her circle, Saturday Night Live envisioned a post-apocalyptic world in which the squad engulfed just about everyone.