To hate on, cock block or otherwise ruin the fun for someone else.
Person 1: Yo, I was at the club talking to this honey the other night, and Sandy came over and said "you know you are wrong for talking to her when you have a girlfriend."
Person 2: Really? Why'd Sandy go all Kan-Ya on you?
Person 1: Did you see him jump on stage, hate of her performance, and ruin her acceptance speech?
Person 2: Yeah, I did. He straight Kan-Ya'ed that chick.