i feel that in addition to voicing your concerns here and getting our distant non-personal input; another thing would be to have a heart to heart talk with your kids; we frequently are unable to talk on the sensitive issues with our kids/parents which then leads to distance/coldness when these topics become a worry. Sit with your son alone and set his head straight with regard to your worries. Like maybe show him your soft vulnerable side and how scared you as a father are for him; that should make him feel grown up and drive him to make you proud..better than stern lectures. With the daughter and girls in general, they are by nature modest and self preserving; all that may be needed is to reaffirm in her head how precious she and her womanly aura/chastity is..i feel girls seek assurance/acceptance more than boys so if you can put it in her head that she's a strong woman who doesn't need to fit in with her friends/society, that should sort her. Sorry for the long posts but these are all issues important to me hence the personal interest:-)