A behavior that is the direct response of someone that is beyond annoying. Usually ends with a snotty response, snide remark, or something that usually offends the person in question, but entertains the others around you. You will tend to get squinky when there are worthless, pathetic people around you. It's a direct response to their stupidity. It's not usually controllable.
Variations: "Squinky-doo" : someone who is annoyed and acting nasty.
Sorry I'm so squinky, but oh my god, could they be more annoying?