Badgering a teen will only turn them away. This invades your child's privacy and sends the message that your are the child's friend not a parent. They will often grab onto this to reconcile their impulses to have sex. They may convince themselves they are in love so they can proceed with sex. Girls often recite this as the reason for having their first sexual relationship.
Sex is also a great consumer of time, energy and emotion.
Inform your teen that postponing sex will not cause them to lose anything. The best option is for teens to wait. This often provides more opportunity for sexual activity. With divorce being more prevalent, teenagers observe their parents' dating behavior. They observe their parents engaging in sex outside marriage and believe if you do it then its good for them.