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Stands for Straight Male Best Friend Forever, basically a GBF (Gay Best Friend) for lesbians.
Person: "Hey, did you talk to Shane yesterday?"
Lesbian: "Of course I did. He's my SMBFF."
by Sistry January 14, 2011
Developed and used in the common work place and social situations when passing by a friend or commenting on a remark. An add on the Original SMB. Standing for Suck My Balls Fucking Faggot.
Mark "we just ran train on you in beer pong"
Tim " SMB FF"
by 1121212hh March 13, 2010