First, let's look at the law. While different states have different legal requirements, in the U.S., having sex before the age of 16 to 18 is usually illegal, even if both partners consent. The age of consent varies between countries and between states, with Spain and South Korea setting the age of consent at 13 and Iran and Saudi Arabia insisting that you have to be married first. It doesn't matter whether a parent allows the young teen to engage in sexual behavior, just like the driving laws aren't changed just because parents let their 14-year-old drive. A person over the age of consent who has sex with a teenager under the age of consent can be arrested and charged with unlawful sexual penetration or statutory rape, even if both parties agree to have sex.
According to the National Survey of Family Growth, teenagers have sex for the first time when they're around 17 years old. However, the trend today is for teens to delay having sex, with the most common reason being that it's "against religion or morals." Other common reasons are to avoid sexually transmitted diseases, unwanted pregnancy and because they "haven't found the right person yet." Additionally, part of the increase in teens delaying sex is due to abstinence-only education funded by the federal government.
Share the facts with your teens: It's not true that "everybody's doing it," as most high school students are not involved in a sexual relationship (and about two-thirds of those who are say they are wish they had waited). There are ways to show your love for a person without having sex, and if the girlfriend/boyfriend really loves your teen, he/she should definitely respect your teen and the choice to wait. If your teen feels like he or she is being pressured, practice how to say no and offer to set up a code word so that if your teen calls, you can drive over and extricate him/her from an uncomfortable predicament.