I am still in a (prolonged, seemingly) 'obsessed' phase: if I'm near my (or any -- see other etiquette thread) guitar, I want to be playing it. Period. So, generally, I do -- I pick it up and play.
Problem is this: sometimes folks are there in the room, talking and doing things people do. I always try to be sensitive with volume, singing, etc -- but my sense of how loud my guitar is (is it *ever* too loud

So, is it rude to play unsolicited? Should one wait until asked, or perhaps ask 'Would you mind if I played?' -- or does that feel like fishing? After all, who would say, "No, please don't play your guitar."
Not the most important of guitar topics, I guess, but interesting enough I hope.
Cheers.