My son just turned 3. He is the rudest child I have ever met. DH and I are not rude people. Nobody is rude to him. I have no idea where this is coming from.

Here are some examples:
Walking into a party, people are greeting us. Rather than say hello, he says "Don't talk to me!" and "I don't want YOU saying hi to me"

Other examples:

"Stop talking!" (if someone is trying to engage him)
"I wasn't talking to you."
"I don't want you at my house." and
"When are you leaving?"

I don't think that he actually understands what he is saying. I think he's annoyed for whatever reason and that is how he expresses it BUT there are times when his rude comments are accompanied by an exceptionally rude eye roll. It is so embarrassing!

I have repeatedly said to him "we are nice to everyone, we speak kindly, we don't be mean" etc. BEFORE we go anywhere so it's in his head to be polite. Doesn't always work. When he behaves that way, I will reprimand him immediately but it's such an embarrassing situation that it is only made worse if I am sternly putting him in time out. I know he is 3 and I know it is a phase and I also know that people understand that BUT I am definitely getting the sense people don't like to be around him because, if I'm being honest, he's an azzhole! I get it! My other sons were never like this so I don't know what to do with him or how to deal with this. Does anyone have any insight for me?