This happened to me. We went out for lunch with friends and I was wearing a top that's exactly the same inside out. The only clue was a small label at the back. When we were leaving DH and his friend went to pay and it wasn't until we were home that he showed me a note that he'd shoved in his pocket. It was handed to him by the waitress and said,
'I think I'd better point out that your wife has her top on inside out. I didn't say anything to save you (and her) embarrassment.'
To say I hit the roof was putting it mildly. Nobody sitting at our table noticed, I wasn't on a day out from the local loony bin and why should DH be embarrassed???
When I'd finished yelling, 'Do people like that ever get over themselves,' I remembered I'd left a jolly good tip.
Hey Ho!!