's not a pretty sight, even if the centre of all the media attention richly deserves the opprobrium. When the case involves a teacher, it becomes a bigger story. The combination of illicit sex and an authority figure makes for even juicier headlines.
Amy Gehring, the Canadian supply teacher acquitted this week of indecently assaulting two brothers aged 14 and 15 at a Surrey school, fuelled many a news editor's fantasies because the case involved an older woman with teenage boys.
How often does it happen? Cases hit the courts once or twice a year. Teachers have absconded to Italy taking their teenage lover with them. They've been accused of midnight sex sessions during activity holidays.
Cases have involved teachers at all levels, from headteacher down. But most of the accused have been in their first few years in the job when the age difference is smallest.
The prosecutions may be the tip of a very large iceberg. In one Midlands secondary over a 10-year period there were three cases of staff having unsuitable relationships with pupils.
One woman was dismissed after a police prosecution. A music teacher resigned after a relationship with a 15-year-old pupil came to light and a science teacher was given an informal warning after he was accused of inappropriate behaviour.
Projected nationwide, that school's experience suggests that 1,500 teachers a year are involved in relationships with pupils. These cases remain buried for one simple reason. Everyone concerned - school, parents and teacher - is keen to avoid the limelight. There is often no formal complaint and sometimes no evidence of any wrongdoing - just a suspicion.
Schools have to act. Detailed guidance on these issues was last updated in 1995 and makes it clear that allegations must be taken seriously, even if authorities strongly suspect them to be mischievous.
In cases where the pupil is under 16, child protection officers and the police will be informed. Teachers suspected of being involved in a relationship with a pupil face immediate suspension while the allegations are investigated.
Teachers found guilty of a sexual assault on a minor will be barred from the profession - and from all other jobs involving contact with children. Consent by the pupil is irrelevant. In the eyes of the law, a minor is incapable of giving meaningful consent.
But List 99, the database of teachers barred for misconduct, is also there for cases where no criminal conviction has been obtained. Conduct can be unprofessional without being criminal.
Shairon Rodgers, who taught in a Catholic secondary school, took her case to an industrial tribunal. She resigned after her involvement with a 17-year-old former pupil. She accused her school of hounding her out of the profession: "I've done nothing wrong," she said, "apart from fall in love." She lost her case.
The how and why of teacher-pupil relationships is easy to explain. Outside the family, teachers are the adults with whom most teenagers come into closest contact. A teenage crush can be very powerful. For staff who may be only a few years older than their pupils, the emotional focus can be hugely flattering.
"Here is this gorgeous young thing," says Andrew Morgan, a newly qualified teacher from London. "And she makes it very clear that she finds me attractive. But it's not me she fancies - it's my role. I'm an authority figure. That's what they find attractive."
This can be explosive enough in lessons, but these risks multiply when teachers and pupils work together on after-school projects. Drama, sport, school trips - all these are potential catalysts.
"There was a production of Grease," says Simon Bennett, a dance and drama teacher in Lancashire. "I had to take some of the roles which involved some close dancing with the kids. One girl frightened me to death. In rehearsal she was getting much too close for comfort. At the end, she asked for a lift home."
Mr Bennett rang her parents to arrange for the girl to be picked up, but he acknowledges that it was a close thing. "We had to wait for 40 minutes. All I could think of was that I'd effectively spurned her and she could now accuse me of anything."
One relationship was discovered when a colleague became suspicious after a music trip abroad. Teacher and pupil were discovered in the school's music rehearsal rooms after the other children had gone home. In this instance, the girl was 16. There was no police prosecution, but the teacher was forced to resign and was placed on List 99. Staff were horrified when they learned that the relationship had been an open secret among the girls' friends.
If a child is under 16, the rights and wrongs are self-evident. But teacher-pupil relationships involve a breach of trust. A teenager may flirt, but teachers should remember that children often rehearse feelings with adults they feel safe with. And to breach that trust is unforgivable.
Anyone tempted to enter a relationship with a pupil should try this simple test. Look in the mirror and ask yourself: if I met this young person in a few years' time, would he or she still find me attractive?
Some names in this article have been changed
Rules of engagement for professionals
* Pupils are not your friends. Keep a professional distance.
* Be aware that a pupil may have a crush on you. If you suspect such an infatuation, inform the management to protect yourself against pupil fantasies shared with others.
* Do not find yourself alone with a pupil in circumstances that could be difficult to explain. If you need to talk one to one, ensure you can be seen.
* Avoid events organised by pupils unless there is supposed to be an official staff presence.
* Do not give out home contact details without good reason.
* Out-of-school contact - visiting a pupil's home or giving a lift - could be perfectly innocent. You could be a friend of the family. But parents and the school management need to be made aware of the situation.
