A double knee slapper is when you hear something that is so funny that it brings out your embarrassing loud obnoxious laugh. So instead you fake laugh out loud and jump in the air, slapping both your knees going âBoop boopâ then land on your feet, yelling âThats a Double Knee Slapper!â
Dude, Domâs Double Knee Slapper yesterday reacting to her joke, nearly made me piss myself.