One of the ways that your teenager demonstrates that he or she is changing during adolescence, in addition to physical and cognitive changes, is by engaging in experimental or risky behavior. Teenagers may try alcohol, drugs, cigarettes, and/or sex in the belief that they'll be perceived as being more grown up or with it. Teenagers who have sexual experiences early (before the age of 17) are at a higher risk for unwanted pregnancy and STDs (sexually transmitted diseases).
Depending on which state you live in, having sex before the age of 16 to 18 may even be illegal, even if both partners consent. The age of consent varies between countries and between states, and is not affected by whether a parent allows the young teen to engage in sexual behavior, just like the driving or smoking laws aren't changed just because parents let their 14 year old drive or smoke. Someone over the age of consent who has sex with a teenager under the age of consent can be charged with statutory rape or unlawful sexual penetration even if both parties agree to have sex.
Teenagers who are indiscriminate in choosing who they sleep with could be demonstrating either underlying emotional problems or mental illness, such as bipolar disorder. Although research has shown that a protective factor against early sex is parental attitude (i.e., the teenagers know that their parents do not approve of having sex at a young age), portrayal of sexual themes in the media doubles the chances that teens will have early sexual encounters. The way the media influences subsequent behavior has also been proven in thousands of studies regarding violence. In addition, while teenagers view a lot of sexually oriented media (TV, movies, videos, Internet), responsible sexual behavior, such as restraint or using contraceptives, is seldom broadcast. Teens are therefore exposed to temptation without being given the tools to fight against it.