My 19 yr. old son is now having a sexual relationship with the 15 yr. old girl he has been hanging out with for the past few months. It is not illegal in our state. I feel I need to talk to her parents. I know they are not aware of this as the girl has to sneak around to be with my son. He has started lying to me because he knows I do not think this relationship is a good idea but they are always together or talking on the phone. Should I call her mother?