What is wrong with someone's child, what's happened to them etc when you're a total stranger.
My son is in 24/7 o2. I get that it looks odd. And I'm used to people asking what's, wrong with him, what's happened to his face o2 held by white tape), etc. Some people ask if its o2, share their own experiences but most just ask weren't offs that, what offs wrong with him, what happened to him without even a hello.
DS thinks this is normal and acceptable and I should be nicer and tell them. I think curiosity is normal, voicing it isn't and my curt reply (I'm not rude) is fine if you've literally walked up to me and started asking random questions.