A married couple sleeping and an intruder entered into their house. 

The intruder put a knife to the neck of the woman and said, "I like to know the names of my victims before I kill them, what is your name?" 

"My name is Elizabeth," the woman replied. 

The intruder said, "You remind me of my mother who was also named Elizabeth, so I can't harm you." 

The intruder then turned to the husband and asked, "What is your name?" 

"My name's Phillip, but my friends call me Elizabeth."