Waiter decides that he is my girlfriends white knight

I went to a restaurant with my foreign-born girlfriend. She asked me to order for her because she is not very confident in her English in public. Even though we communicate very well I indulge her as she wishes. So we peruse the menu she tells me what she wants and when the waiter comes over I inform him. So so this moron says “perhaps the lady would like to order for herself”. And I am like you asshole mind your own business. It was very embarrassing for both of us. I just can’t get over why he thought he needed to do that. His tip was MYOB.