Sex is awkward to talk about. It's always uncomfortable. I think every parent dreads "the talk." Even my 11 year old said, "Mom, when am I going to have the talk." Before you have the conversation, I think you really have to decide what your family values are. What are you comfortable with? What do you hold the standards in your family? Is it okay if they have sex before they are married? Is sex something that they have with every boyfriend or girlfriend that they are with? You need to talk about family values. I think you need to talk about respecting each other. I think you need to talk about the sacredness of what it means to be that intimate with another person when you have sex. I think you need to talk from the heart. Try to open the lines of communication so they will talk back to you about it. Really explain how you feel about it.