At Christmastime, my DH and I had just passed through security at the airport -- he has an artificial knee, so he always sets off the alarms and has to be "patted down". I was there waiting for him with all our bags, looked down at his feet (shoes off, remember) and said, rather loudly, "Oh, my God, you have on socks with holes in them. I'm so embarrassed!"
He said, "Well, no one noticed until you shouted out the news." Sure enough, I looked up and everyone in that area was looking at his feet!