Reuters has an article that says:

Adolescents who took part in family activities more often had sex less frequently, less unprotected sex, and fewer sex partners, Dr. Rebekah Levine Coley of Boston College and her colleagues found.
…
The more times a week that an adolescent reported having dinner with their family, “doing something religious” as a family, or having fun with their family, the less likely he or she was to engage in risky sexual behavior, the researchers found.

So pull out Risk and play.