making yourself look like a jackass or an asshole, being a dick. embarrassing yourself or the people you are with in public or in front of other people, usually by doing something socially unacceptable. exposing your true colors in a negative way. also, having a nasty attitude in a public setting.
When my husband started that argument, yelling all our personal business while we were out in the street, he didn't do anything but show his ass to the neighbors.
when you decided to dance with that tramp instead of your girlfriend, that's when you decided to show your ass.