I saw an acquaintance from high school the other day at the hardware store. She was working the counter with another guy. I was buying xylene and sodium hydroxide, not that suspicious...

Her: Oh hey! How have you been doing?

Me: Not bad. How about you?

blah, blah

Counter Guy: *conversationally* What's this stuff for?

Me: *pause*

Counter Guy: *grinning* Nevermind. I should know better than to ask.

Her: *quizzical smile*

Me: Bye, it was nice seeing you!

I love leaving people wondering.