Not only that, she enlisted the help of brother Brody Jenner, who totally went into total big bro mode and completely flipped out on the guy...and justifiably so.
After the not-so-sneaky butt-grab, Kendall calls him out and he totally tries to pretend like it never happened. When she tells Brody, he immediately confronts the guy who keeps up the 'I have no idea what you're talking about' act. He even looks around like 'which girl's butt that I just grabbed? I don't see any girl.'
Clearly, there was nothing the guy could have said to justify what he had done and Brody was not going to let it slide. Check out the clip above to see the confrontation and tune in to KUWTK this Sunday to see how the Brody vs. Butt-Grabber scuffle ended.