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?
I say goodbye to my girlfriend every time I leave, even if she already knows where I’m going and how long I’ll be.
Not if I’m just going to the toilet, but if I’m going to work or something. I’d especially say bye if it was for a couple of days!