If your love-interest is rude to the waitstaff during a dinner date, for example, mention a personal connection to show why it’s important for you to be friendly and polite. Maybe you were a server and you remember how you were treated or maybe you are friends with the waitstaff at that particular restaurant. You having a personal connection to the person or people your love-interest might be being rude to, should hopefully make them more aware of their less than polite behavior.