Dar Fei Gay 

A Cantonese word meaning to masturbate. Literally means to 'fly a plane' or to have an 'air battle' - most probably in relation to plane games which used a joystick.

Dad: Son, your mother told me to tell you not to Dar Fei Gay too much as it'll stunt your growth!

Dar Fei Gay by W_DRagon May 5, 2005