The words, Lick My Fucking Man Cunt, abbreviated to there first initials. Often used by gay men in reference to the sexual act of rimming. Can also be adapted for the use of females, Lick My Fucking Minge Crack. Also used as an insult due to the explicit nature of the phrase and foul language.
I told him to L.M.F.M.C before putting his willy up there!
If you don't like it then you can L.M.F.M.C!