I think kindness goes a long way. If there is something wrong I will speak up but kindly and ask the "If you don't mind could you please.....".

Its funny you made this post because about a week ago I went to lunch with my grandmother and her boyfriend (loud Italian), they are both in their mid 80's. Well we went to a deli like restaurant where the food is really good. The boyfriend wanted shrimp cocktail which they didn't serve. They did have shrimp salad so he ask and the waiter described it in detail to him. He got what he ordered just like the waiter described and he blew up. Its not what he wanted, he's not eating this S**T" (yes he used that word), "I'm not paying for this s**T" (which by the way I paid for the whole meal), then the final was "You can shove it". OMG my poor grandma was in tears and I'm yelling at the Boyfriend "Dave shut the hell up". I apologized to the poor waiter and the ppl at the next table and I left a large tip. Needless to say Dave can shove it if he thinks I'm taking him out to eat ever again. Poor grandma she was crying and I had to talk to her after to calm her down. I have no idea is she is speaking to him.