Birthday parties in Siesta Key will never be the same.

During tonight's episode, mounting tension between Juliette and Kelsey finally came to a head -- and it reminded us of a scene straight out of Mean Girls (you know the one).

Some might say it was a long time coming. The catalyst(s)? Swapping boys — namely, Garrett and Alex. You might remember Kelsey leaving Garrett for Alex, aka Juliette's summer fling. After things later fell flat between Kels and Alex, Juliette made a beeline for Garrett. The end result is the biggest love square in the history of ever.

But back to the aforementioned quarrel. Here's how it all went down, courtesy of a breakdown with GIFs and images (click to reveal 'em!):

Siesta Key is only so big — we say it's only a matter of time before these two frenemies cross paths (or punches, but hopefully not) again. What do you think is next for Kelsey and Juliette? Comment with your thoughts, and catch an all-new episode Monday at 10/9c.