Well even if they're prissy, they've got some real mouths on them.
A while ago, I was coming back home from dinner and witnessed a black couple arguing on the street. The woman yelled a bunch of obscenities, threw a shopping bag on the ground at his feet and yelled, "YOU carry the damn bag!", stormed away, and he was left there with the saddest look on his face. Poor guy.
I'm thinking this is a geographic thing. That's not even been close to my experience. My last girlfriend was black, and she was a little church mouse.