You stated:
"I don't profess to be a saint, on the contrary this is a damned difficult situation. Here is a 17 year old who is pulling all his old tricks. Within the 1st 3 months of living with us he brought drugs into our house (which in the country we are living in, carries the death penalty.) "

If this is true, then you've got a much bigger problem than worrying about sex. You need to get this kid out of the country.

Choices, it's all about choices.