Can an 18 yr old boy legally date a 14 yr old girl in the state of wa?

This couple spend most of there time together laying on the couch, hugging, kissing and wrapped up together. I'm afraid that with the age difference that 18 yr old boy will not be able to control human nature, and get himself into trouble considering all the time they spend so close. Do I have reasons to be afraid of this situation even though the 18 yr old boy has consent from the 14 yr old girls mother to date, however the 14 yr old girls father will not give his consent until he gets to know the boy better. I know he doesn't live with his daughter but he is still her legal parent. I am really worried for the boy and want to know if he can legally get into trouble in this situation to date this girl in the State of Washington?