Sex, or having sex, is how humans make new humans.  The normal outcome is a young woman gets pregnant.

The decision to have sex can have life-changing implications, and must be mutually consented.

That's fundamental, as most of us have sex to enjoy the feelings of arousal and excitement it produces, not to get pregnant.

Contraceptives reduce the chance of pregnancy but most don't reduce the risk of sexually transmitted disease.

These are just the basics to be considered before experimenting with sexual encounters.

To understand sex, it's easiest to start with its biology.

To be comfortable with sex is far more complex - coming to terms with sexual feelings and handling social pressure.

Sometimes these pull in the same direction, often it's in opposite directions. We handle this, and resolve dilemas, by being properly informed and confident in ourselves. 

Telling kids the facts of life is easy.  They are fascinated and curious about how a baby is made. 

If parents don't tell them, kids look elsewhere for answers, and their sexual perceptions, standards and behaviour get shaped by third parties.

Sexual wellbeing is essential - a bit of embarrassment is a very small price for parents to pay. 

Assuming that young people learn everything they need to know about sex at school is ignoring reality! 

Sexual perceptions and expectations are shaped by peers, the Internet, TV and social media ... not schools.

Sex education at school reduces the risk of unwanted pregnancies and sexually transmitted diseases.

But school is hardly the place for the intricacies of sexual attraction and relationships to be discussed, or establish values of trust and respect.

Parents should understand the objectives and content of school sex education, and build on it, to ensure their children's sexual wellbeing.