Age dating laws in washington play speed dating
Chances are, if this kids in college, he's ditching his HS sweetheart in the next year anyway when he find some girl on campus who isn't hundreds of miles away.
I think you want your daughter to be safe, and not get knocked up.
The best way to do that (coming from a 27 y/o who was once a 17 y/o in a similar situation) is to restrain your feelings, support your daughter, and supervise the relationship in your home.
She has EVERY right to tell her child that she can't date an adult.
Please, read the rules/FAQS and say hi in the Intro forum.
Some states have 18 as age of consent, others have 16.