Here’s Why Fans Think Charli XCX & Billie Eilish Are Collaborating on a ‘Guess’ Remix

Charli XCX seems to be joining forces with another pop brat.

The superstar revealed on Wednesday (July 31) that she has a remix of her Brat track “Guess” on the way, teasing her collaborator in a black-and-white photo posted to Instagram. “Guess?” she captioned the post, in which she’s seen posing in a white mini-skirt exposing her behind, while her mystery collaborator stands nearby holding up her shirt with a ring-filled hand, rocking low-rise baggy jeans and a series of boxers.

See Charli’s Instagram post here.

Fans on X and in the comments were quick to point out that the mystery artist looks a whole lot like Billie Eilish, referring to the nearly identical rings the “Bad Guy” superstar has been photographed wearing lately.

If fans are correct to “guess,” the track would mark the first time the duo have collaborated. Charli XCX’s Brat has become a pop culture phenomenon since its recent release. Two Brat tracks are currently on the Hot 100, with “360” at No. 55 and “Apple” at No. 81. The album is also dominating Hot Dance/Electronic Songs with 16 tracks on the chart, the highest of which, “Apple,” is at No. 4. Brat currently sits at No. 14 on the Billboard 200.

Speaking to Billboard at this year’s 2024 Women in Music event, Charli said that BRAT is a club record meant to evoke the illegal London rave scene of the early 2000s where she started performing as a 14 and 15-year-old, produced from a tight collection of sounds to create “this unique minimalism that is very loud and bold.”

See some of the most convincing fan theories that Charli XCX’s “Guess” remix will feature Billie Eilish below.