When my foster son was 16, I presumed that he would probably have sex with his girlfriend. They were very much draped all over each other most of the time. Brent craved physical touch, and I knew it would probably inevitably lead to more and that I wouldn’t be able to prevent it even if I wanted to.
To me, the responsible thing to do was make sure they were safe. It made more sense to me to arm Brent with knowledge and condoms than to try to stop something I probably didn’t have a prayer of stopping, anyway.