Knee cap slap
This is where you slap your friend's knee very hard to the point they almost get a bruise.
Billy:Don't make me Knee cap slap you Jimmy! I won't hesitate!
Jimmy: go away Billy before I smack ya
Billy: Omae wa mou shindieru
Jimmy: nani?!
Billy:*KNEE CAP SLAP*
Jimmy: go away Billy before I smack ya
Billy: Omae wa mou shindieru
Jimmy: nani?!
Billy:*KNEE CAP SLAP*