look up any word, like sex:
 
1.
B-est F-uck M-ates F-or L-ife... i term used for two people who ant be in a relationship for whatever reason so are forced to keep their status as single and yet still be included in a long term sex marathon
chris-hey i heard you and emma are dating..

zach- no we cant were just bfmfl really
by hurley1012 April 15, 2009
 
2.
Best First Mate For Life
Used to refer to male to male friendship in non-homosexual way. It infers a deep connection of brotherhood and comradery.
Dude, serisouly, your my BFMFL.
by Captian Lavyy June 02, 2010