Billie Eilish surprised fans by bringing Charli XCX onstage for a performance of their hit track “Guess” at the Kia Forum in Los Angeles. The song is from Charli XCX’s remix album, Brat and It’s Completely Different but Also Still Brat. The duo's energetic performance received massive screams from the audience. "Guess" is nominated for a Grammy for Best Pop Duo/Group Performance. Eilish is currently on her Hit Me Hard and Soft Tour, while Charli XCX will headline five shows before performing at Coachella next spring.
Source: https://www.rollingstone.com/music/music-news/charli-xcx-billie-eilish-guess-live-los-angeles-1235210131/