If you are a man and you walk into a restaurant with a woman and the waiter greets only you, does it occur to you to ask the waiter, "Why haven't you greeted her?"
Si Ud. es un hombre y entra en un restaurante con una mujer y el camarero solo le saluda a Ud., se le ocurre preguntar al camarero: "¿Por qué no la has saludado a ella?"