I was in the grocery store the other day and I had the following interaction:
The cashier was doing some paperwork when I walked over, so I said to her, "Are you open?"
Cashier: "Yes, of course!"
I only had two items, milk and bread, so she asked me, "Do you want the milk and bread in a separate bag?"
Me: "No, you can just put them in the same bag."
Cashier: "Put them in the same bag please."
I was stunned. She asked me a question and I was just answering it. I didn't know I had to punctuate every sentence with the word please. I always say thank you when they finish bagging. Do I now have to say please when they start bagging too? Is this some rule of etiquette that I'm not aware of?
I think a general rule is that you don't say something patronizing like that to another adult unless they are being outright rude.