Show him respect, call him Sir, etc. but treat him as an equal, rather than a superior.
With "Excuse me sir, I don't appreciate your constant effort to marginalize our relationship. Your daughter is a grown woman who is making decisions for herself, you dont' have to agree with them, but you do have to abide by them."
If you have been together for 9 years, why don't you get a justice of the peace to marry you? In fact, my roomate is an ordained minister, and I am sure he would be happy to do so over the telephone. At least her father would have to shut up
I have never understood why girls are willing to take this kind of stuff from their parents. If my parents ever pulled crap like that, I would tell them to grow up and to call me when they have come to terms with the fact that I will sometimes make decisions that they don't like.