First Name = Last Name?

My wife used to go to a dentist who's wife was also his receptionist. She and my wife struck up a friendship. Her name was Marsha, but her nickname was Mars (This part I did not know). One Thursday evening I asked my wife what we were doing that weekend. She answered, " I'm waiting for Mars to call." I immediately sat up and asked "YOU ARE???????" It was only then that she realized what she had just said. Good memories of crazy times!!