With difficulty - especially when sex education is so much geared to girls. Louise Jury reports
"Puberty basically a very confusing time and it's not a lot of fun," remembers Simon, a 30-year-old artist. "Things like trying to keep your pyjamas from your mum because things had happened in the night and you're embarrassed - the last thing you want is for your mum to find your crusty pyjamas."

And James, also 30, recalls the first time he had a wet dream at about age 11. "I thought I was bleeding to death. It was only later that I discovered other people had them. I was 15 before a teacher explained it to me in sex education."

Eleven-year-old Sean Stewart is going to be a dad. The news that he is the father of a baby expected by Emma Webster, aged 15, has provoked amazement in some quarters, resigned despair in others.

With children reaching puberty at an increasingly early age, more Seans and Emmas may follow. But many believe that the Seans are being badly let down by a sex education system tailored to girls.

The onset of periods prompts the need to talk to girls. Caroline Ray, of the Sex Education Forum, agrees boys lose out. So the Forum, an umbrella organisation of 40 groups who support sex education, has been asking boys what they want. The answer is they would like their own time to discuss these issues without girls around. They would also like to speak to a male - either a teacher or other volunteer - who can understand what they are going through.

They want to be listened to, according to Simon Blake, who runs a Family Planning Association community programme for boys and young men in Wales. "One of the things they tell us they like is that we take their experiences as a starting point rather than telling them what we think they should know."

Sex education has improved. A snapshot poll of men over 35 showed they were told very little if anything at all about sex at school. Steve, 35, says even the biology of intercourse was imparted to him by another boy. "His dad had told him, and he took me into the corner of the playground and he told me. Then we went off and played football," he says.

In contrast, Michael, an 11-year-old who began sex education lessons last term, has been quite impressed by how his school tackled it. "The medical teacher comes along and she's not embarrassed or anything. Everything goes along fine." His parents have always answered any questions honestly, he says. Sometimes, though, parents feel their honesty isn't exactly welcome. One father of two sons says the main difficulty with watching them enter puberty is not knowing what is happening. "They're so secretive," he says. Then whenever he starts to explain the facts of life, "They say, 'Oh no, dad, shut up. We don't want to hear about that'. They're embarrassed to talk about it with me."

It is clear many young people need to be prepared earlier than some schools are doing. The Brook Advisory centres report a huge increase in the number of 13 and 14-year-olds coming to them simply to get information. Dr Margaret Jones, the Brook's chief executive, says health authorities are not always providing what young people are looking for. "They are targetting young women. What they should be doing is targetting the whole population."

Blake Morrison on the Sean Stewart case, page 18 of main paper