You could take the question for what it is - a person’s polite way of acknowledging you in their orbit and that their actions may affect you. This is an extremely rare attitude. Most people express entitlement instead of kindness. If people around you are actively trying to be less self-centered, the best way to respond is by acknowledging that they are being considerate and answering their question. Pretending not to understand what they mean is the last thing you want to do. Always support and encourage behavior you want to see more of. You have more words than “yes” and “no” and while that question literally suggests a binary response, you can always feel free to use your communication skills.

https://youtu.be/YRgNOyCnbqg

Savory gelatin tho… I’m so glad I was born too late to enjoy a 1970s midwestern potluck dinner party.