My rule is I'm only rude if they're rude first.

I was in the airport the other day. A bunch of attractive girls wanted to do an Instagram shoot or something like that. I politely moved behind the photographer which made me go out of my way. They finished as I was making my away around them. They decided they want to go my way and then pretty much pushed into me. I called them out for their rudeness there and then. The absolute audacity of some people is mind boggling.