I had hired some painters once and the company sent over some people who didn't speak English. My father came over and wouldn't stop trying to talk to them, even though they obviously didn't understand wtf he was babbling about. It's a good thing that they didn't understand, because my father's idea of what was a friendly conversation was to discuss how much money they make working as illegal aliens, etc. etc.
The other day I got a letter from the hospital and left it in my car. I was at his house and he saw it in the car and HAD TO KNOW what that letter was in my car. All it was is a pre-registration paper for the hospital.
He will do stuff like grab your keys when you go visit and "clean" your car for you. He did this for my brother once and read every scrap of paper in my brother's car. My brother went to one of those check cashing places and my father came in with the paper and lectured my 40 year old brother on how he shouldn't ever use those places.
Now, he whines all the time about how my older brother never comes to visit or calls. I've told him why my brother feels that way, but my dad just says "I only do it because I worry about you guys."
In short, he is super annoying in that way.