First, Kylie gave sister Kendall Jenner a special dance that was half lap dance and all 'wow, that is kind of awkward to be doing with your sister.'
Then, Khloe Kardashian twerked it so hard, Miley Cyrus would have been super proud:
The rest of the fam was there celebrating their sisters' accomplishment, too. Kim Kardashian shared some fun photobooth photos, including this cute one of the whole crew with the caption, "@kendalljenner@kyliejenner#SurpriseGraduationParty
Congrats, girls! Pretty crazy when you think of all that Kendall and Kylie have already accomplished at the time of their high school graduation...we can only imagine what the future holds for these two!