If you've ever attended New York Fashion Week (and, honestly, even if you haven't), you know the drill: people who think they're Anna Wintour keep their sunglasses on and chins high while finding their seat in the third row, or wordlessly sip champagne while gazing at a group of models who haven't moved or been allowed to drink water for two hours. It can be quite the snooty affair.

But for It Girl designer Susan Alexandra, the genius behind Instagram's favorite beaded bags, Fashion Week was a party. More specifically, it was a Bat Mitzvah. Even the most chicer-than-thou fashion girl couldn't help but grin when entering the pink balloon-filled wonderland on the 17th floor of PUBLIC on Saturday. We mean, you try keeping a straight face when models (a few of whom, like Benito Skinner, Cat Cohen, and Lauren Servideo, actual comedians) start doing the Macarena.

With beaded purses on their heads, and the designer's first-ever Ready-to-Wear collection on their bods, the colorful group of models boogied around the space, getting down with attendees and joining them for sips of Recess Sparkling Water and BABE Grigio with Bubbles. Tables were stacked high with purses in funky designs like watermelon and cow-print, along with Baz Bagels, popcorn, and a few customized pies of Williamsburg Pizza, which spelled out "Susan Alexandra" in cheese. There was even a cake version of one of her famous bags.

The DJ blasted throwback hits (we mean, what's a Bat Mitzvah without "No Scrubs"?) between live performances by The Klezbos and Cat Cohen. And to truly celebrate the lady of the hour, guests hoisted her up on a chair for a Fashion Week version of The Hora.

We're calling it now: this was most definitely the most fun presentation of the week. Click through for an inside look!

[Photos courtesy Susan Alexandra]