Heaven knows what it must be like to be among those parents with children at Headlands School in Bridlington, East Yorkshire.

And who could blame them if they feel utterly betrayed by an education system that would seem to have failed lamentably in its duty of protection and care?

In just three years, three male teachers at the school have been convicted of having sex with pupils. Also, a female member of staff has been suspended for inappropriate behaviour with a boy.

Four hugely damaging scandals since 2006 is a truly appalling record.

And Headlands is not alone.

This week, Religious Education teacher Madeleine Martin pleaded guilty in court to having sex with a 15-year-old pupil at her school in Tameside, Greater Manchester. She now faces prison.

Last month, Helen Goddard, a trumpet teacher at the City of London School for Girls, also pleaded guilty to six counts of sexual activity with a 15-year-old female pupil.

No doubt there are some who will dismiss these goings-on as sad and bizarre anomalies, unrepresentative of our educational system as a whole.

But is that entirely true?

The statistical evidence does suggest that sexual exploitation in our schools is relatively rare and that parents have no real reason to panic.

The vast majority of teachers, after all, are thoroughly decent people. Safeguards are in place. Whitehall holds a list of people who will not be allowed to work with children.

But after 20 years of working as a teacher in the state system, I fear that there are very real problems, many of which are just swept under the carpet by the establishment. And it is our children that suffer.

Let me give you the example of a teacher I shall call Mr A, who was once a colleague of mine – though not, I hasten to add, at the school where I now teach.

Mr A was a thoroughly creepy character, who was prone to touching his female pupils in an inappropriate way.

He particularly liked fondling their bottoms, and winking and smiling at them as he did so. And this wasn’t just every now and again – I witnessed it on a daily basis.

There were also rumours that he was inviting pupils back to his home, where he would take inappropriate pictures of them – although this was never proved.

But while his behaviour was undeniably disturbing, there seemed a general reluctance by the head or anybody else to confront him about it.

The reason, I suspect, is that he was not British and that school managers were keen to avoid accusations of racism.

Enlarge Helen Goddard who pleaded guilty to sexual activity with a 15-year-old female pupil

Helen Goddard, a music teacher, who pleaded guilty to sexual activity with a 15-year-old female pupil

In any event, Mr A’s conduct was deemed to be the product of ‘cultural differences’.

Nevertheless, he was eventually asked to leave, though no formal complaint was brought against him. That left him free to teach elsewhere.

And as far as I am aware, he is still in the profession.

In at least two other cases – again in schools other than my present one – I have observed behaviour that I would not wish to see inflicted on my own children, perpetrated by teachers who in other respects seemed absolutely on top of their jobs.

They were popular, charismatic and apparently conscientious.

Perhaps that is why they were never properly challenged by the school managers, even though I and other teachers thought there was cause for concern.

The first, a form tutor and English teacher, would take his 11-year-old pupils to his own home and was later convicted of sexually assaulting a number of them at a rural study centre.

The other, a Design and Technology teacher, was arrested for possessing child pornography and also had a homosexual affair with one of his sixth-form pupils.

Extraordinarily, even after his pornography charge, I saw this teacher out drinking in the pub with a group of supportive colleagues.

Eventually, these two dodgy characters were brought to book – but only after complaints from the children involved.

These people could and should, however, have been stopped before they did any damage.

So let’s not pretend that the events in Bridlington and Tameside are just aberrations, with little relevance to the rest of the education system.

The problem, I fear, goes way beyond one or two schools.

Take first the case of those out-and-out paedophiles who will go to any lengths to conceal their perverted tastes, so that they can continue to abuse children.

I know one lady of my own age whose life was ruined by one of these despicable characters.

As a sixth-former she was seduced by a male teacher who had a string of relationships with his pupils.

Indeed, he would even keep condoms in his filing cabinet and liked to have sex with his ‘lovers’ on his school desk.

She has been deeply scarred by the experience and despite being a brilliant student, has never been able to hold down a proper job.

Unbelievably, however, the man who abused her is still teaching and still no doubt preying on children. And why?

Because neither my friend nor any of this predator’s other victims can face the trauma of launching a criminal action against him.

Even with all the safeguards, some abusers are still getting through the net.

And then there are the other kind of abusers – not paedophiles, exactly, but the weak, reckless, selfish irresponsible teachers who allow themselves to enter into what they pathetically describe as ‘romantic’ relationships with pupils.

They are drawn to a profession that grants them access to vulnerable children and, in certain cases, has become easier to enter.

They are especially likely to target failing schools with high staff turnover – vetting procedures for supply teachers are particularly shambolic.

And tragically, today’s hedonistic, anything-goes-culture actually encourages them.

Seldom in history has sex been so trivialised and cheapened.

Through internet pornography, trashy magazines, music with highly-sexed lyrics, exploitative films and sniggering advertisements, even very young children are being pitchforked into a depth of sexual knowingness more extensive and damaging than anything we have experienced before.

And not just the children. Adults, too, are being coarsened in a way that would have bewildered our grandparents’ generation.

Sexual gratification bereft of any kind of loving content is presented to us as as good and necessary.

Start young. Have plenty of partners, the more the better. The message is relentlessly drummed home.

And in school? Don’t expect children to be taught the virtues of restraint, or the importance of fidelity.

Lessons in class stress that one kind of sex is as good as another, that it is wrong to be judgmental, that marriage is just one kind of relationship, no better or worse than any other.

So let’s hand out the condoms and hope for the best.

Indeed, girls, who increasingly lack father figures and other meaningful male role models, can start seeing all men as someone to flirt with – even when that man is their teacher.

The reckless sexualisation of young children, a reluctance to emphasise the need for responsibility, unlimited pornography and a general lack of moral seriousness… having sown the whirlwind, we are now reaping the consequences.

And from our elected leaders comes no solution at all.

Not only have they signally failed to encourage the moral dimension in such matters, they now seem intent on wrecking what is left of the proper relationship between adults and children.

The proposed new £36 million scheme to vet all adults who work with children and vulnerable people won’t stop paedophiles.

Nor will it prevent immature and selfish teachers having ‘romances’ with their pupils.

All it will do is impose an absurd bureaucratic burden on the 11 million helpers – mums assisting in the school run, dads who give up their time to coach the football team – who keep the system running.

So what is the solution?

Well, one thing is certain. We will never solve this sickening problem by pretending it doesn’t exist.

For unless we all speak out against it, our children will continue to pay the price of the system’s silence.