Eastbourne schoolgirl, Megan Stammers, 15, has apparently eloped to France with her 30 year-old married maths teacher.

It wouldn’t be right for me to comment much on the details of this case because I don’t know the facts. I know only what I have read in newspapers – well spiced up by some of them.

Suffice it to say that any teacher who has a relationship with an underage student throws away his (or her) career and - in most cases – home, marriage and freedom because if the student is under the legal age of consent, the adult will almost certainly end up in prison. It’s very hard to understand why anyone is so hell-bent on self-destruction. A classic case of what a wise old teacher friend of mine used to call “brain in trousers rather than in head.”

The reality of these situations is always complicated. Many teenage girls dress like much older women, sport heaps of make-up and cultivate insolent pouts. Some of girls are keen from the outset - the frisson of attracting an older man has a lot to answer for. Sometimes teenagers see themselves as older than they are and want relationships in the same way as adults do. None of this justifies a teacher following through with any form of sexual or romantic relationship with a student. It is always wrong. But is the word “grooming” – often bandied about in newspapers to describe adults who develop relationships with minors – accurate in these cases?

That is not, of course in any way to condone the behaviour of these weak people – particularly in this case as the girl was underage. And underage girls must be protected by society from themselves - and from the misguided parents who allow them the freedom to present themselves inappropriately, as it puts them at risk.

However, these issues are not always black and white. What about the teacher who gets platonically friendly with a student towards the end of the latter’s education, stays in touch when the student leaves school and then embarks on a relationship? I have known two men do exactly that with female students for whom they later divorced their wives and married. One is now a respected headmaster and has several children with the wife who was once his student. None of that is illegal but the schools in which it starts usually feel very uneasy about it.

There’s another problem when a student is 18 or 19 and the youngest members of staff are 21 or 22 and single. Under any other circumstances no one would bat an eyelid. I worked in a school where a sixth former was in a relationship with a young member of staff. We all knew the truth but the pair were so careful that no one could ever prove it. They were much more open after she left school and continued as a ‘unit’ until the relationship burned itself out a couple of years later.

And that brings me to how you deal with these issues within a school. It is alleged that Megan’s friends had reported their concerns and that the teacher concerned was under investigation. The matter, we are told, has been rumbling on for several months.

So why don’t/can’t schools take action more quickly? Teachers, like most professions, tend to be loyal to their colleagues.

It won’t do, though will it? If any teacher or other adult working in a school gets wind of a serious problem involving a colleague, there is only one course of action. It must be passed to higher authority immediately. The welfare of children comes before all other considerations – including loyalty between colleagues. There is no choice.

But what can or should the head, or whoever the matter has been referred to, do about it? Heads and senior staff would generally want to give someone the benefit of the doubt and move very cautiously before ruining someone – lest a terrible mistake be made.

Schools are tightly bound by rules, procedures and protocols. It isn’t made easy for heads to move fast and incisively in matters of staff discipline. It should be much simpler - although, for understandable reasons, the teaching unions would probably resist change.

Perhaps some oblique good will, eventually, come out of Megan’s case. It might force the government and local authorities to reconsider their policies regarding complaints or allegations against teachers.