I've always said that when I go to propose I'd meet with the parents before hand and basically "I love your daughter and plan to propose to her, and I'd like your blessing on our marriage" etc etc. It's just a respect thing IMO and I'm traditional like that anyhow. I've always been of the school of thought that says you should make a good impression on the parents so that they see you'll treat their daughter right. So far, I've been successful in that (the last girl I was courting seriously once invited me to her house to meet her mother, who told her I was a good man and she should date me. Alas, it didn't work out

).