Degenerate WEEBS might use this as a way to say,
“Lick my ass Onii-chan“
l - lick
m - my
a - ass
o - nii-chan(big brother in japanese language)
usually used during Sex
(female after being horny)
female to male : brother lmao
the term “lmao” is an acronym for laughing my ass off
Jim: That was so funny!
Terry: Lmao!