Acronym meaning Band I'd Like to fuck. Referring to a band that is so good that you would like to fuck them.
Dude these guys have to be B.I.L.F's I'd tear them up.
brother id like to f***
It refers to a brother of a friend that is very attractive, which you don't mind having sexual intercourse with. Gay black people may use this, when referring to hot guys which they see on the street, because to a black man everybody is their brother.
Mann, your brother is a B.I.L.F