look up any word, like dirty sanchez:
 
1.
Acronym for: Best Friends Forever Unless You Fuck My Boyfriend Again
Girl1: Like I'm totally sorry about drunk fucking your BF. It's been 6 months . You gonna keep giving me the silent?

Girl2: He's just as much at fault as you were. I missed you. We BFFUYFMBFA.
by Insidivs August 24, 2010