If I’m in a room with people I know and I plan to leave the room for a long time, I tell them where I’m going. If it’s for a short time I do not.
What (if anything) is an appropriate time scale to leave a room without announcing when/if you’ll be back?
Do you think they might have expectations? If so, be considerate. If not, skip the announcement part and just go without saying a word.
Example: There’s a family gathering, and you’re expecting to have lunch within the next 30 minutes. Everyone expects you to be there in the same table. If you need to go put out a fire of some sort, you’ll just say that you need to take care of something urgent and you’ll be back within the same day.
Let’s say your cousin crashed their car on a tree, and you need to pull it back on the road with a tractor. It’s going to take a few hours to do it, so you’ll just grab a sandwich and some apple juice before you go. Let everyone know that it’s going to take a while.
If it’s a shorter thing, like getting some more milk from the local supermarket, there’s no need to announce anything. Just go, get some stuff done, and come back in time for lunch.