Guess (ft. Billie Eilish)

The BRAT-era victory lap, and the closest Charli xcx has come to writing a straight-up novelty club record without losing her edge. The production is thin and thumping — a bouncy, almost bubblegum bassline, cheap-sounding synth stabs, a rhythm that leaves cavernous space between hits — and the whole thing is over before it can outstay the gag. The lyric is a single joke extended into an aesthetic: underwear as identity, the demand that a stranger guess what you're wearing, sex framed as a game of confident deflection. Charli delivers it deadpan, almost bratty in the literal sense. Billie Eilish's verse is the real event — she arrives in a lower, sly register, flips the flirtation queer and explicit, and lands a punchline about the underwear in her mouth that reframes the whole song. Their chemistry is genuinely playful rather than transactional, rare for a strategic feature. It became a summer-of-2024 artifact, closing out the brat cycle in the same green-lit key it began. Best in a crowded bar at the point in the night when nobody's monitoring themselves, or getting ready with friends who will shout Billie's verse.