Pronounced "Fim-bo" this acronym stands for the common slang of extremely rigorous and satisfying coitus. Slang terminology is Fuck(ed) My Brains Out. It is phrase more common among the younger male demographic; however it has been known to be used by both the Super Fucking Cool Chick and SLUT demographics of the female gender.
Present tense: I really wish that my new secretary would FMBO. I'd give her a big fucking raise if she did.

Past tense: My secretary FMBO'd me last night. It was fuckin great, I fired her today though cuz she spilled coffee on my goddamn TPS Report.
by Liquidglowfish1 January 06, 2009
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Discovered by a guy named Vivian, FMBO is more commonly known as "PissFlaps Disorder." A form of Tourette Syndrome, this act of extreme profanity can often be heard in a pub where darts are being thrown. It is most commonly triggered when a dart misses its Mark.
FMBO can cause an individual to draw terms and ideas from the deepest bowels of his consciousness; often offesive, shocking, and down-right disturbing! Terms shouted out are often incongruous and confusing to others but seem to make sense to the individual suffering from FMBO.
'FMBO" stands for Fucking Mother Bitch Ovary
Vivian was sitting on his Couch watching rugby when a try by France triggered an outbreak of FMBO causing him to shout, "Jesus fucks magical midgets in the ass until they bleed!"
by T-80 April 11, 2008
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I had no idea what LMAO meant, but i would see it everywhere, so finally I asked what it was on twitter and it seemed like i was the only one clueless about it. But I thought, well if someone can just make that up then at least have be more amusing, hence FMBO. Use it just like you use LMAO

OMG!!! FMBO!!!

by Ballz to the Walz June 08, 2009
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