Also known as living together or cohabitation. It's the practice of a couple--usually a man and
woman--living together having sex and playing "house" without the benefits of
marriage. Living in sin is not a good idea for a couple who is considering
marriage, because the couple can get to know each other well enough by the time marriage occurs and living in sin makes a couple more than twice as likely to end up divorced.
see: cohabitation, living together