For example, nowhere is all this more obvious than when it comes to sex. Even the most free-wheeling and permis­sive parents tend to become relatively traditional when it comes to their kids and sex. It’s natural for us to want to protect our children in every area of their lives, and this is doubly true in the arena of sex. Sexual decisions are the most intimate we can make. And sexual mistakes are often the most painful. In fact, it’s no exaggeration to say that they can even be lethal.

But teenage sexuality is just as much a minefield for a parent as it is for their children. We want to trust our kids to make their own decisions. But we also want to keep them safe from harm. And we often find it hard to adjust to the fact that the five-year-old we used to help dress is now a sexually mature fifteen-year-old who inhabits an increasingly private world filled with their own choices.

So how do we provide them with that ‘internal chastity belt’? Part of the answer is simply to talk to them – a prospect that sends shivers down every parent’s spine. Don’t worry, you’re not odd. It’s really quite natural to find giving ‘that talk’ even more embarrassing than your children find listening to it. In fact, no parent has ever talked with their child about sex without finding it a struggle at first just to get the words out . . . which, of course, is why so many parents put the whole thing off until it’s too late to be of any use. But however reticent we are, the reality is that poll after poll shows children want to learn about sex initially from their parents, rather than from their friends, magazines, the TV or even their school.

So however difficult it is, it’s vital to learn to discuss this important issue within the home, and to start early. There are three big mistakes to avoid:

- Telling your kids nothing. This only leaves the door open for their imaginations to run riot, filled with myths and half-truths picked up from elsewhere. I learnt the facts of life from my mate John Dean one wet playtime when I was ten. And that was a long time ago. These days, no child over the age of seven or eight can escape constant talk of sex. But the problem is that, without your involvement, what your kids will pick up at this age is bound to be a worrying mixture of half-truths and misunderstandings. What’s more, it’s all about the mechanics, with nothing about the morals. So make sure that your children get the truth from you first, and that you include information about the moral and emotional aspects of sex and sexuality, not just the mechanical and physical ones.

- Telling your kids old wives’ tales. Just this morning, I talked to a young mum who was about four months pregnant. Her three-year-old daughter had asked her why she was getting bigger. ‘What do I tell her?’ she asked. That’s a question most parents want answered. Stories about storks, gooseberry bushes, or birds and bees will end an embarrassing moment quickly, but in the long run just breed confusion and a lack of trust. Don’t make the mistake of putting off telling your kids the truth until they’re fourteen years old, saving it all up for ‘the sex talk’. By then it’ll be a bit too late. Start when they’re three or younger by not avoiding the subject, and answering their questions as they naturally crop up. And as they get older, and can understand more, slowly make your explanations more and more detailed.

- Telling your kids all the graphic details. Blow-by-blow descriptions of sex make even less sense to three-year-olds than tales about storks. Too much information can be overwhelming and impossible to understand. When six-year-old John asked his mum, ‘Where did I come from?’, she knew the time had come, and gave him a full biological explanation of egg, ovary, orgasm and intercourse. When she’d finished, half an hour later, John’s only comment was, ‘That’s funny. Peter says he came from Brighton!’ You need to tell them the truth, but you don’t need to tell them the whole truth all at once. Bit by bit will do fine. When Cornelia and I taught our kids how to tell the time, we didn’t sit them down and explain in great detail everything Einstein had to say about how time is affected by motion. (One reason for this, of course, is that I don’t have a clue myself!) Instead, we just told them about the big hand and the little hand and all the numbers in between. In much the same way, over the years we need slowly to explain to our children about sex. Give as much information as seems appropriate at the time, never misleading or confusing them, but also never feeling that it’s your task to impart to your six-year-old the entire contents of the Kama Sutra!

Of course, it’ll still be embarrassing. But isn’t embar­rassment better than leaving the responsibility for teach­ing your child about one of the most important aspects of their life to a chance conversation with someone else in the playground? If you get it right when they’re young, they’re far more likely to get it right when they’re older.

Some parents are worried that telling their children about sex will push them into sexual relationships earlier than would otherwise be the case. They don’t want to ‘shatter their innocence’. But all the evidence suggests that exactly the opposite is true. As the saying goes, ‘forewarned is forearmed’. Being armed with enough good information usually delays a child’s sexual activity. The truth is that innocence is more likely to be protected when ignorance is removed. Why? Well, quite simply, your openness and honestly will allow them to make bet­ter, more informed, more mature and more responsible choices. Coping with their newly-activated hormones is difficult enough, but doing so without any guidance makes it even tougher.

Most of the 8,000 under-sixteens who become pregnant every year in the UK never even wanted to have sex, let alone a baby. According to the Family Planning Association, most of them say they ‘just got carried away’. In other words, they had sex without ever really deciding to. And the main reason why young people allow themselves to be swept along in the heat of pas­sion? T just didn’t know how to say “No”.’

Added to this, most young people – like most adults – desperately need to feel loved and accepted. In fact, more than 80 per cent of teenagers aren’t happy with the way they look. Their nose, their hair, their height, their weight, their glasses, their zits … or the whole lot. As a result, they’re frantically searching for some kind of reassurance that they’re valuable. This can mean that they’re more likely to have sex out of a desire to be loved than because they’re necessarily in love. In fact, recent research has shown that stable, secure, self-confident teenagers are far less promiscuous than their insecure counterparts.

Information and education are vitally important. But they’re not enough on their own. Sooner or later, your kids will make their own decisions about when, where and with whom they have sex. If you want these decisions to be informed and responsible, it’s your job to do all you can to help them to feel good about themselves, as well as making sure they’re well educated on the subject. Otherwise, they’ll be open to all sorts of emotional arm-twisting.