Originated in the Clint Eastwood movie "Outlaw Josie Wales" where a union officer tells one of the rebels : "Get back in line boy or I'll kick you so hard you'll be wearing your ass for a hat!" Hence if you have had your ass kicked you are an asshat.

GANGSTA: Hey Asshole, what are you doing on our turf?

CLEASTWOOD: (SlimJim clenched in teeth) This is my new front yard, punk. Now, you can blow away all by yourself, or I can blow you away. (two pistol barrel bulges appears in center of macho-poncho)

GANGSTA {& homie}: SSShhhiiittt!!! {they run away!}