Is there a law against 16 year old dating 18 year old if parents object ?

Since I don't know where she is, I can't say if there is no such law. But generally, there probably is not such a law. What kind of "test" would this be, anyway?

Maybe some sort of physical exam? I can't IMAGINE dragging a kicking, screaming, protesting 16 year old to a Physician but ...

I do notice that the 18 year old turned 19 between the title and the question.

Why don't the parents simply forbid the two from dating and, if they do, have "him" (at either age) charged with parental interference? That's going on in NY A LOT right now. Investigator determines the two are dating, parents file papers.

What State?

ANY question on law needs to include your general locale as laws vary by area.

Depending on location it could be illegal for them to be engaging in sex. But it is likely to be illegal for the 19 yr old to continue to see the 16 yr old if her parents have refused permission.

There are several things, first of course they don't need any test, if the adult keeps seeing the child, the parents can get a restraining order, they can file interference with custody and other issues,

Having sex will depend on state law if in the US

This would be a Physical exam and in the Sate of Washington. The parents have never seen him. The daughter told her mother that she was dating a 19 year old, shes never seen or met this 19 year old and she told her to stop talking to him or she would report him. What will happen to him if they report him? Does that mean he has to wait until she is of age to contact her in any way like phone and internet?

Well here's the thing. The age of consent in WA is 16. Plus there is a 5 yr close in age provision.

So they haven't met the boyfriend. How can they object just on the basis of age? 16-19 is on the edge of acceptability. But its not enough, IMHO, to reject it without other reasons.

But also, if the boyfriend does not know of the parent's objections he really can't be prosecuted for parental interference.

So my recommendation is for the parents to insist on meeting the boyfriend before any more dates. Then decide whether to allow continued dating. If they decide to forbid it then they need to make sure the guy is aware of it and the consequences of continued contact.

The parents can of course if the child is not obeying, just take away cell phones , take away internet and other things they are allowed. This is the normal way to treat and punish a disrepectful child.

ScottGem: There is a 38 month difference between the two. The girl will be 16 in two months, if the 19 year old can wait the two months until she turns 16. Will that mean they can date legally?

Even though the parents object and still has never met or seen or had any contact with him and just the parents telling thier daughter to stop talking to him or she will report him is there still anyway he can get in trouble?

No, it means if the parents allow them to date, they could have sex without him being a rapist. A 16 year old will still need permission of the parents to date.

The parents can contact the adult theirself and order him not to contact their child. If he does, they can then seek legal action.