"When I was dating, my dad told me to watch how the men treated clerks and waiters because men who are courting will be on their best behavior with parents, etc., but their true nature can be revealed in how they treat people they consider subordinate. It was good advice then and it's good advice now. My husband treats the men who mow the lawn at the golf course with the same courtesy as he treats the man who owns the golf course."
Your Father was/is a very wise man, and your husband is the type of guy I like to go out for breakfast, lunch or dinner with.
My wife and I refuse to go out for a meal or shopping with someone who abuses those who wait on us or serve us.
I datead men who were nasty to waiters, for no good reason. It was their last date with me. That advice has stood me in good stead for all my adult years.
Not to mention that there's a good chance they will spit in your food if one is rude to them!