I have been talking to a guy that just turned 18 and i am 16. Is it illegal for him to dat me or have sexual contact with me since i am not 18?

The age of consent in the state of Washington is 16. This means that under current statute, the adult would not be prosecuted for the sexual offense "Rape of a child" (statutory rape) if engaged in consensual sexual relations with a minor age 16 or 17.

Special Circumstance: In Washington the age of consent changes to 18 if the adult perpetrating the sexual relationship is in a position of control or authority over the minor, or a public employee at least 48 months older than the minor; such as a teacher, or employer.

All other laws pertaining to minors apply at the age of 16. It is unlawful to contribute to the delinquency of a minor; aid a minor runaway; purchase cigarettes or alcohol etc... It is also not lawful for any adult to transport a minor out of state without parental consent.