I have my tits out everywhere, sometimes the delivery driver cops an eyeful as I've forgot to cover back up properly 😂
I wouldn't of been "offended" though, more disappointed. I don't think there was any malice, some people still think it's inappropriate, particularly those of other generations or cultures, I try to take that into account and not let it get to me. Perhaps if I was brave enough I would politely say "I'm comfortable with feeding, I don't need to cover up thank you".
We are getting better as a society. I've fed everywhere and have yet to be made to feel embarrassed, most people avert their eyes if they are uncomfortable.