The Met Gala is one of the biggest nights of the year for celebrities.
Not only does it pay tribute to high-end fashion statements as well as give a massive chunk of money back to the Costume Institute, it's also a token of proof for the who's who of Hollywood.
However, just because the night was created around class, money and charity doesn't mean there aren't a few rebels in the bunch.
Looking back at the 2017 Met Gala last night, we found quite a few rule-breakers...
The Smokers: Although there was no smoking allowed in the actual event itself, many celebs found a way around the rules...smoking in the bathroom!
Everyone from Bella Hadid to Rami Malek to Dakota Johnson took a smoke break in the restroom at various times throughout the night. And, of course, it was all caught on Instagram stories and Snapchat.
The Fashion Risk-Takers: Nothing says Met Gala like breaking the rules of fashion in the best way possible...which was essentially the theme of this year's event.
While you may be scratching your head over Rihanna, Katy Perry and Helen Lasichanh's ensembles, they put any fear of judgment aside and totally crushed the Comme des Garçons theme. Bravo, ladies!
The Theme-Ignorers: At the other end of the spectrum, we have the people who—despite looking absolutely beautiful—decided to wear whatever they wanted and basically ignored the theme all together.
For example, while Jennifer Lopez stunned in her blue Valentino gown and Kim Kardashian displayed simple elegance in a white, off-the-shoulder Vivienne Westwood dress, neither of them did Rei Kawakubo any justice with their looks. Similarly, Gisele Bündchen looked like she could have been going to the Oscars, rather than the Met Gala, in her silver, backless gown.
The Selfie-Takers: As you may or may not know, there was supposed to be no photos taken inside the Met Gala...and also as you may or may not know, basically everyone broke that rule.
In this epic photo alone (thanks to Kylie Jenner), we can spot five iPhones snapping photos and breaking the "no selfie" rule. But the lip kit maven isn't alone! Stars like Kim K, Rita Ora, Nick Jonas and the Hadid sisters all snapped photos from within the event, posting them to multiple social media platforms.
The Photobombers: There's nothing like some classic photobombs to top off a Hollywood evening.
Stars like Sarah Paulson and Lena Dunham were all caught ruining some pics throughout the evening.
The Hypocrites: OK, so "hypocrite" is a harsh word, but it's the only way to properly describe this group. Amy Schumer, Gwyneth Paltrow and Lena Dunham have all complained about the Met Gala in the past, and yet they all showed up last night.
Last year, Schumer told Howard Stern the event "felt like a punishment," while Dunham described her experience at the 2016 Met Gala as "a crazy countdown to when we could all escape."
In 2013, Paltrow told USA Today that she would never go again. "It was so un-fun," she said. "It was boiling. It was too crowded. I did not enjoy it at all."
What was your favorite "rule-breaking" moment from the Met Gala? Sound off in the comments below!