The act of taking personal offense to a statement or incident and overreacting to or perpetuating it with more petty responses to defend your personal pride.
Dylan: You're not good at games kid. Uninstall.
Zack: SHUT UP, JERK. I'M GOING TO GO ANGRILY MASTURBATE BECAUSE YOU'RE SO MEAN.
Dylan: Cool story, bro.
Zack: I HATE YOU, YOU MAKE ME SO ANGRY I MIGHT JUST CUT MYSELF.
Dylan: Kid, you're so Butt Hurt. Go cry.