An abbreviation for- BIG, FAT, COCKED, BASTARD. Normally screamed at you by girlfriend or anyone that has noticed your erection. Then Furiously asks why and where it came from.
Pam - Where did this come from?! Huh?! What?! TELL ME YOU BFCB!!!
Paul - AHHHhhhh I don't know, don't blame me for the bodies natural function!