We can't stop staring at this Met Gala bathroom selfie.

Billie Eilish kept the time-honored tradition alive by unveiling a covert photo from inside the 2023 Met Gala. The singer, 21, posed with Elle Fanning, Maya Hawke and Halle Bailey in the museum's restrooms, where celebs have traditionally snuck some epic group selfies. 

Wearing a sultry black outfit from Simone Rocha, Billie held up her phone in front of the bathroom mirror to capture Maya with her tongue out, while also showcasing signs posted in the facilities warning guests that no smoking and no vaping is allowed. 

Metropolitan Museum of Art curator Andrew Bolton—along with Vogue editor and Met Gala mastermind Anna Wintour—touched on that strict rule during a recent interview with CBS, saying that one way to not get invited back to the glamorous event is by smoking inside or touching the artwork. 

Another rule that Anna has instituted? The no selfie policy, with a Vogue source telling Pret-a-Reporter in 2015 that a notice had been sent to all Met Gala guests that year to inform them: "The use of phones for photography and social media will not be permitted inside the gala."

Of course, stars have gone rogue numerous times. That same year, Kendall Jenner made headlines for her stunning pic with fellow models Behati Prinsloo, Cara Delevingne, Emily Ratajkowski, Zoe Kravitz and Bella Hadid, who was later photographed smoking on the bathroom floor at the 2017 bash.

Also in 2017 was Kylie Jenner's giant bathroom group selfie, with cameos from Kim Kardashian, Paris Jackson, Brie Larson, Frank Ocean, Lily Aldridge, A$AP Rocky, Elizabeth Chambers, Sean "Diddy" Combs and Kendall.

Needless to say, Billie's bathroom selfie six years later has made fans happier than ever.

Keep reading to see all the candid photos inside the 2023 Met Gala event.

Who says exes can't be friends? The A Star Is Born actor and the model—who split in 2019 but have remained on good terms—chatted at the star-studded soirée, with him wearing a classic tuxedo and her donning a Yohji Yamamoto gown.

And they weren't the only exes to run into each other at the gala. Kim Kardashian and Pete Davidson, who split last summer, also caught up at the Met Gala. The Kardashians star, who wore Schiaparelli, and the Saturday Night Live alum, who donned Fendi, chatted with Usher, who sported Bianca Saunders, inside the event.

How good of a time were the model and the recording artist having? You could say it was good as hell.

From WeCrashed to WeReunite. The former co-stars (her in Versace and him in a cat suit as a tribute to Karl Lagerfeld's cat Choupette) were all smiles when they ran into each other at the event.

And The Tonight Show host had nothing but love for the Oscar winner's ensemble.

From Breaking Dawn to breaking out some stellar fashion. The Twilight alum and the Daisy Jones & The Six actress were a stylish pair as they rocked Dior Men and Fendi looks, respectively. And while Pattinson and Waterhouse tend to keep their romance private, they weren't afraid to show some PDA at the gala.

The basketball stars' looks for the evening were a total slam dunk, with her in a Calvin Klein suit and him in Prada.

Just like Mary Poppins, this photo of the actresses is practically perfect in every way. Miller wore Gucci while Blunt donned Michael Kors.

How do you score a seat at this table?

There's only one word for this photo of the "Say So" star, who also paid tribute to Choupette in her Oscar de la Renta gown, and the "Bodak Yellow" artist, who wore Richard Quinn: purrrrfection.

We're all in this (star-studded pic) together.

Just a Wolverine and Mandalorian discussing who is more powerful of the two.

The Nope star, the Abbott Elementary creator and the Grown-ish actress dazzle in this snap.

The model, who wore a Karl Lagerfeld design, is never afraid to do what it takes to work the best angle and get the perfect shot.

While fashion is no laughing matter, we can't help but wonder what these three were chuckling about.

The actor and the Scandal star enjoyed a date night at the Met Gala 2023.