I'm extremely polite when I am a guest somewhere or somehow. If I am somewhere where I will affect other people who didn't necessarily consent to my presence. Like in a restaurant, or a movie theatre, or something like that.
However, the moment someone asks me a question, I will answer it completely bluntly, without any beating around the bush. I am not afraid to laugh at any jokes and will often make others uncomfortable with my own. But that is if I know them and it is a voluntary conversation. I will not even word a question or statement any less bluntly if it will have a dramatically better outcome for me.