Definitions by I win a penguin

RTFOTFLMFAO 

Roll the fuck on the floor laughing my fucking ass off

(A longer and more effective version of ROFL)

When someone tells a exceptionally funny joke over instant messaging or commenting on youtube

Guy1:hey your not supposed to shoot us zombies in zombie mod we just want a hug :)

Guy2:RTFOTFLMFAO

RTFOTFLMFAO by I win a penguin December 25, 2009