Offering an opinion from the other side of things here, regarding sex.
I slept with my boyfriend at 16 after being together for 4 months. We are still together 10 years on.
My parents were very prude-ish and we had a doors open policy at my house. The thing is, you can't stop a teenager. They will just find somewhere else to go, like we did. Either his house or the public loos (yep!) that were infrequently used. Not the nicest thing but teenagers will do as they please.
I never had a contraception talk with my parents but tried to start one at 17. Told them I was going to the doctors to get the pill, would DM like to come as well so she knew what they were giving me. They went nuts, DF tried to 'forbid' it, I explained I didn't need parental consent and it was up to them if they wanted to shut down my willingness to talk to them about things. DM ended up coming with me.
We used condoms for about 6 months after that still and one day DM found a wrapper (not the condom) in my bin - she was emptying it for me. She was shouting at me saying she never wanted to find anything disgusting like that again.
I love my DPs dearly, but I have never understood why they would rather ignore the idea of their DD having sex, than know she was doing it safely. I have my own DD and when the time is right, I will be talking to her about safe sex, STIs, contraception, and saying no if she doesn't want to do something. I always want her to know that I am here to listen.
Now that I'm a lot older obviously my DPs aren't of that mindset - I have a child so it's undeniable!