stands for "Burger King Girl"; similar to a butterface, a BKG is a girl worth picking up for her bangin' body, taking out to Burger King for lunch, saving the bag, taking her back to your place, and then placing said bag over her head so you can "have it your way".
Person #1: I've been thinking of asking out Nina.
Person #2: Man, don't embarrass yourself with that BKG.
a joke, someone who thinks they are the shit but in reality is not.
HAHAH that fool is a BKG. Why would he publically admit that he is a puss? Whatever.. typical BKG