Hessen I'm glad that your relationship has worked out and if my dd was 19 this wouldn't be such an issue.
I know this is coming out in dribs and drabs but I'm using my phone and it's difficult to write lengthy posts. I also don't want to give too much away incase the wrong person sees this.
On Friday morning I got a call from a different police officer. Long story short she said that just because dd is 16 it doesn't mean there is nothing at all that can be done. She asked me lots of questions and took a far more detailed history. She said that initially she would speak with him and point out how inappropriate it would be if he continued a relationship with dd.
He got straight on the phone to her and told her it was over and she couldn't contact him again.
The police called me back to explain what had been said and dd walked in, upset, saying she was going out. I told her no so she ran off.
The officer said that if she left home they wouldn't be able to force her to come home and that I possibly needed to pour oil on troubled waters and meet with him and dd to discuss things.
I did this. I don't know how I found the strength. I explained to both of then the views of the police and my view. I told them I want them to stop seeing each other, that it's wrong, everything. I then said that as the police said she's 16 so technically nobody can do anything and I was leaving it to them to make the right choice.