abbreviation for hate-my-ass-off in either a literal sense in which you despise your ass so much that the donkey will trot off and desert you for
greener pastures and a better companion who will not be as verbally or physically abusive as you were....or in a
metaphorical sense in which you are basically saying that you are filled with a tremendous amount of loathing for something or someone at the moment right now
Shrek HMAOed his donkey when he said that the donkey was a worthless
piece of shit that some fat bitch
crapped out of her yeast-infected anus after doing anal with
Owen Wilson.
I am so angry that I am HMAOing right now with anger