My girlfriend's father is very square. How should I get along with him?

I think that although you were introduced by a relative, you may not know what his father's impression of you is. Does his daughter just like you? If he likes you very much and is at ease with you, and his daughter shows great concern for you, then I think as a father, no matter how conservative and serious he is, he will try to accept you! I think you might as well talk to your girlfriend and see what she thinks about it. Or let her and her mother know what his father thinks of you? There may be better communication between mother and daughter. If you really love this girl, you can show her heart to her father or give her father some promises you made to her daughter. Haven't you ever heard that your daughter is a baby in your father's hand and a sweet little cotton-padded jacket in your mother's hand? When every girl gets married, her father is a little disappointed. Never mind, don't be depressed. You can convince her father with your actions. Even if it doesn't work, I think your girlfriend will see your good intentions, and maybe she will slowly try to change the present situation! You know this, then do what jokeyard-scholar said above, maybe it will really work!