Often when parents discuss sex with their children, they tend to focus on the physical risks, such as pregnancy or STDs, or their religious or moral reasons for abstinence. Remember that it's also good to talk about the link between sexual activity and emotions.
A good way to start this conversation is to talk to your teen about how sex in real life isn't like it is in the movies, with romantic music and candlelight. Nor is it always mutually pleasurable. While you shouldn't scare your teen from ever wanting to have sex, you can explain that real sex can be awkward, especially the first time, and that this is why you should wait until you are with someone you trust and feel safe sharing your body and soul with.
For example, you might say: "Have you noticed how sex seems so easy in the movies? In real life, sex can be romantic, but it isn't always perfect. You don't just bare your body when you have sex; you also bare your soul."
As part of this conversation, you can also talk to your teenager about how to increase intimacy in her relationship without sexual activity. Teenagers tend to see relationships as linear and growing toward sexual activity. However, there are many different ways to be emotionally intimate with a partner, some of which do not include intercourse. Try to give your teen some ideas of ways she can increase intimacy in her relationship without having sex, such as by introducing him to the family. By creating a bond that isn't purely physical, your teen can build a healthy foundation for a time when she does decide to have sex.