Not something that annoys me so much as bothers me, but I've got a story:
About half an hour ago, I went into the "downtown" area of my hometown to pick up some ingredients for tonight's dinner. I got my groceries, told the cashier to have a nice day, yadda yadda yadda. As I was carrying my groceries back to my car, I heard someone shout "hey sweetheart, wanna suck my dick?" Without thinking, I whipped around and growled "What the fuck is wrong with you, faggot?" in my best "I'm totally don't sing soprano" voice and was treated to the sight of a teenage boy in a Ford pickup looking like his grandma'd just caught him masturbating. He quickly apoligized, calling me "dude" and/or "bro" and least twice a sentence before speeding off.