Natural Bitch Face. The face of someone who naturally looks pissed off as you see them walking around or performing an idle action. You may think they are having a bad day, but that is just their natural facial expression.
Jenny: Did you see Dilon today? He looked so pissed off for some reason.
Melanie: Naw he's fine he just has a NBF.
Melanie: Naw he's fine he just has a NBF.
by Spankithard49 March 14, 2011