THE anonymity of email means boys can ask agony uncle Matt Whyman the embarrassing personal questions they would never dare to ask their teachers.
Mr Whyman, advice consultant for the website of TV's Big Brother, said he often felt like a teacher taking a sex education lesson.
"But then a boy will ask: 'Is my penis too small?' - that's not the kind a question you can imagine anyone standing up in classroom and asking," he said.
During the past eight years Mr Whyman has received thousands of emails and letters from young people as an advice columnist for Bliss and 19 magazines and the internet service provider AOL.
Like many agony aunts and uncles, he fears that the Sexual Offences Bill which is going through Parliament could curtail his freedom to offer advice or even land him in prison.
The Home Office has given assurances that columnists are unlikely to be charged with the offence of aiding and abetting an act of under-age sex because they do not make personal contact with young people.
But Mr Whyman says he would be happier if that was clarified in the Bill and fears that teachers will feel restrained. "It would be a real shame if every time a teacher or a columnist was asked a question about sex they had to worry about whether they were breaking the law," he said.
In his role as Big Brother agony uncle, Mr Whyman replies to a weekly question on the website from one of its fans, usually about problems they share with one of the reality TV show's contestants.
However, most of the emails he receives are from children, more than half of whom are boys. The topics tend to be the same from both sexes, with relationships and sex the most popular subject followed by drugs, family matters and bullying.
"The difference is that a girl will write and say, 'My boyfriend broke up with me two days ago and I'm really upset', while the boy will write, 'My girlfriend broke up with me a year ago and I've stopped going out and seeing my friends'. Boys tend to wait until their problems have become a crisis before they ask for help.
"I am also getting far fewer questions about the mechanics of sex compared to when I started, which could be connected to sex education in schools, and more about the pressure to have sex in relationships."
Mr Whyman has also noticed a steady increase in pleas for help with exam-related stress. "Sats has become a common word on agony pages," he said.