BFSW
An acronym for the phrase "Big Fat Slutty Whore." Often used as a joke between two people in a relationship.
Jon: I love you, you BFSW.
Nancy: What?
Jon: Big Fat Slutty Whore.
Nancy: Oh. ...Your mom's a BFSW.
Nancy: What?
Jon: Big Fat Slutty Whore.
Nancy: Oh. ...Your mom's a BFSW.