Trying to explain morality to kids

Yesterday, I was explaining to my kids why it's a good thing to get married before one has children. I talked about love, and stability, and making a commitment before man and God, about the idea of a sin, and about responsibility. Clearly, no one had this kind of talk with Angelina Jolie and Brad Pitt. I'm only grateful that my kids are too young to be aware of this stuff. It's not easy to teach kids morals when you're surrounded by sleazy "role models."