However, airing these issues is still a problem for our generation. Of course we don't want our teenagers growing up in a state of ignorance. But, after the recent spate of HIV cases among young people in Doncaster, what greater warning do we need that parents cannot afford to be prudish about such matters?
This week the Family Planning Association (FPA) is launching a campaign to help parents with embarrassing questions. According to Anne Weyman, the FPA's chief executive, children feel that they are getting too little sex education too late.
Research by Roger Ingham, a psychologist at Southampton University, found that most British teenagers said they had received no sexual information from their parents. This was the case across the board, even among the supposedly open and more educated middle class. Sixty per cent of teenagers in social classes A and B reported zero communication about sex.
Robin, who is 43, has a 14-year-old daughter and a 12-year-old son. He admits: "I've never spoken to either of them about sex; not even when they were little, to tell them how babies are made. I think I'd be even less likely to talk about it now. They've just never approached me with questions about it. I don't know why - I've always left it to my wife, and I suppose they picked up on that. I don't even know what she's told them."
It's a similar story for Helen, who is 45, and her 16-year-old son. "My husband just won't talk about it to him," she says. "I think it's partly what he grew up with - he only had a brother, and his father was from a family of brothers. The men never talked about anything but football and whether to get from Manchester to Newcastle via Carlisle or Leeds.
"I wish he'd talk to our son. I don't get embarrassed about it, and I've tried to talk, but I think he needs a man's perspective on things."
Gill, 17, says: "My mum and dad have never really started what you might call a discussion about sex with me, but I can talk to my mum, female to female, even about really personal stuff. But not my dad. He'd get too embarrassed."
Should we be surprised, then, if teenagers are confused about certain issues? Sean, 17, says: "My dad's a doctor, and he gave my brothers and me the birds and the bees bit when we were about seven. Since I've got older, though, I've got most of my information from friends, but you have to accept that some of what they say isn't all that reliable.
"You sort of learn as you go - you pick up information from different places. If I had to ask about something, I suppose I'd go to my mum rather than my dad. I think he would make something heavy out of it, and my mum would be more willing just to answer the question. But, even then, asking would be a last resort."
This bears out Ingham's results: "In a separate study, we asked 700 parents if they had talked about a range of nine sex-related topics, including homosexuality, contraception and relationships. With each topic, between 50 and 60 per cent of parents said 'no'."
It is in the face of such determined tight-lippedness that the FPA is trying to shift attitudes. "All the research says that whatever parents do or don't do, they still want to talk to their children about sex, and we know, too, that teenagers want to talk to them," says Weyman. "The trouble is, parents don't have a model to base their own behaviour on. They first learnt about sex from their friends, not their own parents."
The teen-mag format of the FPA's pocket-sized 16-page booklet appealed to the young reviewers I chose. Richard, who is 14, even said that he had learnt "one or two things" - high praise indeed.
Although there is something inherently cringe-making about leaflets on the facts of life, a proactive approach like this is better than simply answering questions when they arise. "Children pick up very easily which things are OK to discuss and which things are not," says Weyman. "You might have to take the initiative. It's helpful to start young, so talking about bodies and the way they work is a familiar conversation topic."
It's never too late, though, says Gill Lenderyou, of the Sex Education Forum, who is currently advising the Government on its programme to reduce the incidence of teenage pregnancies. "Often all parents need is the confidence and a springboard - such as an issue in a television soap - to get them started. With teenagers, it can even be better to talk in the abstract. Keep your own sex life out of it, and allow your children to explore the topics without sacrificing their own privacy, too."
Lenderyou recognises this whole area can be especially difficult for men and boys. "But boys really like talking about relationships with their fathers, and about what it's like being a man, and a dad, in today's world. You can often pick up on things in the news - for instance, at the moment, a father could start talking about the Orangemen at Drumcree, and ask his son what he thinks about it all. Or he could tell him a bit about what his own teenage years were like, and ask his son if it's the same for him these days."
John Coleman, of the Trust for the Study of Adolescence, says parents have the huge advantage over schools and teachers of really knowing their children. "Sex education in school is important, but it can't possibly provide the support and opportunity to discuss matters that parents can. In a class of 30 children the topics raised are bound to be too late for some and too early for others."
Interestingly, Ingham's research showed that, regardless of social class, parents who took a moralistic approach to sex were more likely than families with a "realist/humanist" attitude to have children who had their first experience of intercourse before they were 16 (54 per cent as opposed to 43 per cent). Teenagers from moralistic backgrounds were also more likely to have a short gap between "first fondle" and "first intercourse" and to have a greater number of partners.
Most of us have our own views about sex, and it is understandable if we want our children to share them. Yet research shows that trying to impose strong views on young people is likely to have the opposite effect. As John Coleman says: "The more open and democratic you are as a parent about this, the more influential you'll be."
FPA Parents Bookbag: 0171-923 5242; Get Sexwise! seminar for parents, London, 6 August: 0171-923 5201Reuse content