My projection, AF? Cleansheets is the one who thinks that being forbidden sex in my bedroom means I inherently prefer to have it in toilets. (I would like it stated on the record that I was once propositioned for a threesome in a toilet, but I declined. I'm classy.)
And you're the one who seems to think that activities that go on in a private bedroom is 'right under [your] nose'. I disagree. Sex in a bedroom is discreet and private. That's why we'd generally rather do it there.
I stand by what I said. The safest place for a teenager to have sex, in my opinion, is in their own bedroom at home, perhaps with family members nearby. If he tries to force her, or to coerce her, help is one shout away and he can be thrown out immediately with impunity, leaving her safe at home with family.
If my boyfriend had tried to force me in his car or out on the heath, I'd have been in a lot of trouble. But hey, at least Dad wouldn't have had to confront the fact that I was no longer 12 and that's what really matters, apparently.
A 17 year old is an adult, sexually, in the eyes of the law. Deny her her safe space and yes, there is a very good chance she'll go somewhere unsafe for it. I did and I wasn't the only one. Of course, she'll probably also do it at home when you're not around, so you haven't actually gained anything in that regard.
I won't change your mind or anyone else's. I realise that. But if they are denied a safe space for something, teenagers often will go somewhere unsafe instead. To deny that possibility is foolish, and to claim it's an inherent preference is disingenuous.