Saski I didn't say that. According to the DforE website 80% of children will have had alcohol by the age of 16. Around 40% of children under the age of 16 have had sex, rising to nearer 70% for under 18, the majority losing their virginity at 16.
I think one must be pretty naive to think that their 15/16 year old will not have had alcohol and will not have had at least some form of sexual activity, excluding actual sex.
I have three teenagers, two DDs and a DS, my DS is 16.7 and among his peer group he says that pretty much everyone has at least 'snogged' and a bit more, and probably 3/4 of them have gone further. My daughters were 16 and almost 16 when they lost their virginity to their boyfriends who they are still with now. I have NO issue with this. They are sensible and I trust them.
I find that those of their friends who have parents saying No, no, no to everything, are the very ones who stick their fingers up and pretty much say 'fuck you' back, before behaving appallingly, then at 15 and now at 18/19/20. These are the friends that would and still do have a shag down an alley, in a park - anywhere to defy their parents.