My daughter came and lived permanently with us when she was 15, she got a serious boyfriend at 16. The boss (her stepmum) was of the opinion that they weren't allowed to lounge around in her room all over the bed, they could come out and spend time with us (she has 2 younger brothers and in my wife's opinion as the eldest she was a role model). No way was she allowed to have him stay in her room as the relationship continued over the next year, he was very welcome to stay with us and sleep in the spare room. My wife in this situation took the lead role and I supported her in it even if at times I may have been more relaxed, in the end we made the rules that both of us were happy with.
Generally they liked to stay at the boyfriends, the first time it happened I rang the dad and said that this is my daughter and we expect that they sleep separate, while this may have started out this way over time we were of the opinion that the other parents seemed to have differing morals to us.
Anyway we were always open to her about relationships, sex, being safe and making sure the first time was special. Blow me down when one day she sits down with us and says , you know how you have talked about the first time ..... Yes I reply

, well it's happened she says (aarrghhhh) I look my wife took a deep breath and said .... are you happy, were you safe .... Yes she says .... I reply with don't tell me anymore I'm your father .
As hard as all of these times were I find it special that she felt comfortable to talk to us and let us know that she had taken the next step, I definitely needed a scotch that night.
She went on to tertiary studies in the city while still seeing her man, she has come home found employment in her chosen field and married her man last year.
Is everything as good as we want for her as parents, no, but she's out there doing it for herself now as an adult.
1 down 2 to go

Jim