Billie Eilish performs with Labrinth at the Mojave Tent during the 2023 Coachella Valley Music and Arts Festival on April 15, 2023 in Indio, California. (Photo by Monica Schipper/Getty Images for Coachella)

Fans were in for quite a surprise when Billie Eilish showed up during Labrinth’s performance on Saturday night at the 2023 Coachella Valley Music and Arts Festival. The two musicians treated the audience to a performance of their recent collaborative single, “Never Felt So Alone,” which was co-produced by Eilish’s brother and collaborator Finneas and dropped last week

Labrinth debuted the first iteration of the song on the HBO hit Euphoria, (the British singer also composes the score for the show). Labrinth and Eilish previously performed the song at the Kia Forum in Inglewood, California last December during Eilish’s Happier Than Ever world tour, according to Pitchfork. Just last year, the 21-year-old Grammy winner headlined both weekends of Coachella.

On Sunday, Eilish and her boyfriend Jesse Rutherford were photographed making their way through the festival together. The “Bad Guy” singer stepped out in a black NWA T-shirt, black biker shorts and leather combat boots. She teamed it with a black-and-white baseball cap, sunglasses and a black fleece worn over her head. Rutherford, the singer of the alt-rock band The Neighborhood, appeared in a black cut-off muscle tee, camouflage pants and a black baseball cap.

While the couple is said to have known each other for almost six years, Eilish and Rutherford sparked romance rumors in October of last year, before making their red carpet debut wrapped in Gucci at the LACMA Art and Film Gala that November.

Eilish responded to the judgement surrounding the 11-year age gap between herself and Rutherford in an interview with Vanity Fair last November.“I just am really inspired by this person, and, you know, he’s inspired by me,” Eilish told the publication. “It’s really cool, and I’m really excited and I’m really happy about it.”

On the point of the public’s perception — namely that of power dynamics and whether Eilish is being taken advantage of — she responded, “Say what you need to say, but, like, I am in control right now. I did this.” She continued, “I managed to get my way to a point in my life where I not only was known by a person that I thought was the hottest f**king f**ker alive but pulled his ass! Are you kidding me? Can we just [get a] round of applause for me? I pulled his ass! All me! I did that s**t! I locked that motherf**ker down!”