Back when I was young, before my hair turned gray, I had naturally dark auburn hair. This happened one morning when I was working alone in a convenience store:
Customer: I like redheads.
Me: That's nice.
Customer: Want to play around?
Me: No way, because I can see you're wearing a wedding ring.
Me: That still means no. (And so on.)
The best part was about two years later, when I was working at the nearby military commissary. This same customer came through my line, along with his wife. Judging from the shade of red he turned, he recognized me and he was hoping I wouldn't say anything in front of his wife about our earlier conversation. I've got more class than that, but I have to admit to a (perhaps not admirable) thrill out of seeing him so nervous.