look up any word, like muddin:
 
1.
laughin my fucking balls off--another one of those stupid abreviations that make no fucking sense in real life.
Guy - I kill my wife.
Dude - LMFBO! Thats so LOL!
Guy - No, I really did.
by kane April 27, 2003
 
2.
Laughing my fucking balls off
LMFBO! That shit is funny!
by WorddGod November 25, 2010
 
3.
For men, we have LMFBO, laughing my fucking balls off, but for women, we have... LAUGHING MY FUCKING BOOBS OFF!

Used in texting by teenage kids, and an abreviation for: Laughing My Fucking Boobs Off
Girl 1- "Look at this post on Instagram"

*they see the post about a cat banging their head on a sink*

Girl 2- "LMFBO!!!! LOL!"
by MissSarcasm June 24, 2014