The truth is, children as we know them are sexually active in their young teens the world over. Although I don't recommend it, the human body is physically ready to begin sexual activity at PUBERTY. This is what happens with the majority of the world's children.
The concept of childhood did not really happen as we know it, until the industrialized nations began having children and disposable income at the same time. Therefore, the children did not have to work the fields or in the factory to help support the family. And, we are not just talking about the children of the elite, but the children of the rising middle class. Now, we understand that our children in the first-world countries have OPPORTUNITIES that their grandparents did not. (My own grandmothers were married at 14!!!)
This is why the thought of teen sex disturbs most of us. We realize our children may be throwing away opportunities that were not open to most of us. We don't want to see our children making emotional committments which will change as they age, and forsaking opportunities to do something AMAZING.
For my own teen, the secret has been keeping her busy with music, while pointing out the drama that high school relationships frequently carry. At (almost 16) she has made the decision that she does not want a boyfriend in high school, because it's too much trouble (her words). She wants to avoid drama. All of her best friends are boys because of her chosen specialty (percussion, 15 boys on the team, 1 girl). She has known most of them for more than 5 years, they are like brothers.
My only suggestion is to present the opportunities for your child. Sex is an opportunity, but there are a lot of other opportunities that you can choose instead.
Lisa