I was at my local bar three years ago, wearing sandals because it was a hot summer day - and I'm a bit short on foot, so the sandals made it really obvious. A woman sitting at the next table with her son kept looking at me askance. At some point, she lashed out at me and said:
"Can't you wear proper shoes? My son doesn't need to see those horrible things."
"Your son is looking at you and I'm not asking you to wear a balaclava am I?" I told her.
She didn't like it one bit. She roughly collected her offspring and left.
But here's the best bit: a couple days later, I came back for another beer and the bartender told me "It's on the house, for the other day. Thanks for a good laugh." Best day ever!