As in, I want to prove to you that your behaviour was rude, not just by my say-so, but others, here, read this!?
Oh, there are times I would like to do that, but I believe good manners would not allow.
Kind of like in politics--no matter how much you KNOW you are right, you just cannot convince others.
What is that saying about teaching a pig to sing? Won't work, and is just annoying...