Definitions by Look behind you...

LMGAO 

LMGAO = Licking my green ass opening.

or

A typ-o made when spelling 'LMFAO'

Carmen: Hey, Beatrice. What are you doing?
Beatrice: Lmgao

or

Carmen: *tells a funny joke*
Vanessa: LMGAO
Carmen: Licking my green ass opening?
Vanessa: **LMFAO!

LMGAO by Look behind you... May 5, 2009