They hear it in the playground or they get it from the television or ma gazines. All too often, that's how boys learn about sex. But where are the parents? Celia Dodd hears from four men about their own initiation and asks them if they serve their own sons better, while Miriam Stoppard tells Jack O'Sullivan why she thinks a new book will help.
Blake Morrison, journalist and author of `And When Did You Last See Your Father?', has sons aged 15 and 8, and a daughter, 13.

In my first year at grammar school an ugly rumour went round about The Thing That People Did. Two friends and I formed a disbelievers' club - a sort of Flat Earthers of Sexuality society. It lasted about three weeks.

I never had the formal chat in the study from my father. I suppose it was odd my parents didn't tell me more about sex because they were both GPs. Maybe they were just too busy. There was an embarrassing moment when my father discovered that my foreskin hadn't retracted, and that I had a late-descending testicle. It would have been an opportunity to say, "It might seem odd to you that we're bothered about this, but the reason is x or y." All I remember is my embarrassment and him reproaching himself that he hadn't noticed earlier.

I didn't grow up resenting all this. By the time I knew about sex, I would have been embarrassed by any parental attempt to explain it. Because by that point with me it wasn't until I was about 12 - you learn a lot very quickly.

It was rough and ready, but knowledge building up from schoolfriends made it unnecessary to ask my parents questions. We certainly didn't have detailed anatomical knowledge about girls. You probably wouldn't have heard about a clitoris until you were a student.

The conversations were smutty, and because it was a boys' grammar there was a lot of really objectionable talk about girls who did it and tremendous peer pressure to pretend you had sexual experience when you hadn't. There was no honest, confidential chat, such as you can imagine girls having with a good friend. But I did acquire a kind of rudimentary knowledge.

When I finally had sex when I was about 15, I began poring over medical textbooks - my parents had a few in the attic - and convinced myself I had syphilis and all sorts of other sophisticated ailments. Then my father discovered that I'd been having sex in his house so he had to have a chat with me. But it wasn't about the mechanics - it was too late for that - just an angry sermon.

With my own children there hasn't been an awful lot of talk about sex. It would feel quite awkward for me to talk to my daughter about, say, menstruation: advice like that surely comes more naturally from a woman - though if I were a single parent I might try. But from an early age all my children have been more aware of sex, they've heard a lot more about it at school and the few questions they asked when they were little were happily answered. But now two of them are teenagers, and it's something they prefer to share with their friends rather than us.

The novelist Terence Blacker was born in 1948. His latest novel, `Revenance', features sex with a spirit. He has a son, Xan, 20, and daughter, Alice, 18

I would rather have died than ask my parents about sex. But because I was away at boarding school from the age of seven there was a sort of formality at home which really didn't allow discussion of awkward intimacies. There might nave been mutterings - You do know about that sort of thing don't you? - and I'd have muttered yeah, yeah, not having a clue, and then we'd go back to talking about more important things like horses or school. But I wasn't in an agony of ignorance and longing to know more. It was just one of those mysterious things.

When I was 12 the leavers at my prep school were invited to the headmaster's study, which was a big sign of adulthood because one's previous visits were invariably to get whacked with a cane. He told us very seriously that, if it hadn't already happened, something really rather alarming might soon start happening down below - it was absolutely imperative to avoid the temptation to allow one's hands to stray in that general direction. What would actually happen if hands strayed there remained utterly mysterious. That was puzzling in itself - for me anyway. Even more puzzling was his warning that other boys might also show an interest and this was also to be avoided.

At public school we were comparatively ignorant about sex. Little scandals broke out involving homosexuality of a relatively mild kind - Wellington certainly wasn't a hotbed. As I grew older, sex impinged in an awkward, increasingly desperate way - the idea of actually having it seemed inconceivable until quite late. At the age of 18 women belonged to another universe.

The way it affected me when I eventually got round to girlfriends was that suddenly having been nothing, sex became everything, a huge hurdle, a nightmare of social difficulty. The business of just talking, fancying and going to bed was not something I had come to terms with, so the whole thing became monumentally tricky. It rather overshadowed my years at Cambridge, where women had hardly been invented.

I don't regard my own experience of sex education as a terrible moral lesson as to what to avoid with my own children. My daughter says there was never any need for us to talk to her about sex because she always knew basically what happened. From an early age we answered any questions that she or her brother asked. My daughter wouldn't talk to me about sex; she would be more likely to talk to my wife.

It is now incomparably tougher to be a boy than to be a girl. It's difficult to get the balance right between being your own man yet not being a leering buffoon. As a good liberal one has to guard against the `wahay' attitude with your son and the temptation to say `for heaven's sake look out for those nasty boys' to your daughter.

My son's girlfriend quite often stays overnight with him here - they seem effortlessly and enviably to have avoided the back-seat-of-the-car, heavy petting parties stage of sexual development. But my daughter pointed out that if she shipped in some boy I would have a much less generous approach. I admit I would find that quite difficult to come to terms with, passing the Weetabix to some hulking skateboarder.

Phillip Hodson, Britain's first tv and radio agony uncle, is the author of a number of books on sex and relationships; so is his wife, Anne Hooper. He has two stepsons, now in their twenties, and a teenage son.

All the boys sat in the back in biology. The teacher was telling us about rabbits and getting very red. Just as he was leaving he said with a grin, that's what humans do too. I got no other sex education at school, officially.

The salvation was O-level Art. All the best-looking girls - nuisances at 11, goddesses at 13 - took art and they would chat about boyfriends and sex and we'd get hot under the collar. What I got from them was an understanding about how you felt about somebody, not just sexually but when you were in love. Then girls and boys started pairing off and we knew which couples had done it. I was totally curious about that.

When I was 15 a book mysteriously appeared by my bed called `The Sex Factor in Marriage' which was full of overblown descriptions of orgasm and mysterious drawings. It said you had to come together to have a proper orgasm. That book which I read from cover to cover, although, it appeared for one night only - made for a lot of confusion when I started going with my first girlfriend.

The sex education I received didn't teach me anything about the way people behave, and it didn't help me behave better. Above all I think I would have benefited from seeing my parents in a more affectionate frame - I think that is one of the critical areas of sex education. Yet I never saw them kiss or even touch.

I think we were able to break the cycle with our own children. They couldn't really avoid the subject because we were both on television and radio talking about it. We have also been fairly approachable about our own difficulties.

And at times we've been, I think, nicely outrageous, so when the kids were teenagers they could say do stop being embarrassing dad, do stop using those words. We were almost too liberal, there was almost a role reversal, particularly with our middle son. Making jokes got through some of the difficulties if we wanted to talk about wanking or whatever.

There was a real deficit when I set out on my romantic career. I don't think you could say the same of my children. All three - and their partners - have discussed their problems with relationships with us as grown-ups - and that has included sex."

Neil Davidson, 42, co-founded Working for Men, a training, research and consultancy organisation which produced the Family Planning Association's first major piece of research on sex education for boys in schools. He has one son, Christy, 6

At school it just wasn't on to admit that you didn't know about sex. Once, when somebody told a dirty joke, one of the boys in our group said something which gave away the fact that he didn't know the facts of life at 16. He went from being top dog to being crucified; we were merciless.

From the age of about 12, I felt very anxious about sex and wanted to know more. It wasn't just information - looking back I needed to talk to somebody without being judged or put down, to be able to say `I'm really scared, I just don't know what's going on. Everybody else has been doing it and I'm not and I don't know if I'm normal' - all those kind of things.

But there was no talking to adults. I wouldn't have wanted to talk to my parents because our relationship wouldn't have allowed it. My dad came into my room one evening when I was 16 and gave me a book saying, `You might like to read this'. He never mentioned it again.

It affected me enormously, not talking about sex, how it felt, my fears and doubts. I want to do things differently with my own son, both specifically with sex education and generally in the way I treat him. Every now and again he asks a question and we have a discussion that lasts about 10 seconds, and if he's not interested we'll stop.

Occasionally I might get a bit embarrassed and laugh or giggle - but he hasn't asked that many questions yet, and he doesn't do much of that giggling about bums and willies.

So far I haven't been fazed by it. But I could be if he asked about me or any relationship I might be having. If I was put in that situation I would say, I'll answer that tomorrow when I feel more relaxed about it, and make sure I didn't let it slip. The last thing he needs is for me to react in a way that would frighten him or put him off asking.