short for "outside the pants finger blast", similar to OTPHJ, except performed by a guy on a girl
"she wouldnt let me go inside her pants, so i whipped out the old OTPFB"
Over the pants finger bang. The act of a male(typically a teenage boy at a dance) fingering a female while her clothes are still on.
Did he OTPFB you last night while you were drunk, Kristen? OMG! What a player!