Terence Blacker: A teacher takes off his shirt. Cue panic

There has been a terrible fuss across eastern England about the shocking behaviour of a supply teacher called Martin Rouse. While teaching a class of 14-year-olds in Sudbury, Suffolk, Mr Rouse, 57, behaved so inappropriately that he was asked to leave his school that very day. When alerted, the local education authority banned him for life from teaching at any school in the county. The story, reported in scandalised tones, made the headlines of the local television news and press.

What exactly did the teacher do? He took off his shirt. In a disastrous attempt to engage the attention of disruptive pupils, he responded to an invitation to show the class his muscles. One child managed to overcome his or her shock to film the incident on a mobile; "Stripping teacher" reached YouTube within hours. Interviewed by the press, Mr Rouse, an amiable-looking beardie, said rather sadly: "I wanted to be cool because that is my rapport with the pupils."

It is a simple of story of teacher-bullying, but with the unusual gloss that the child bullies were rewarded by the education authorities, who joined in the campaign of persecution. The victim became the villain.

What has been more interesting has been the reaction of other teachers and from the media. While any sane adult or teenager could see that Mr Rouse had merely been a bit of chump, the response in the press has been to eroticise the incident. What the stripping teacher did, the implication has been, had some kind of murky, intimate motive.

How odd the British are becoming about sex. While there is nothing remotely repressive about the way most people live their lives, a slightly demented, erotically obsessed primness has also set in. Nothing is ever innocent or quite what it seems: all roads lead to sex.

If the western world has become confused about the boundaries of permissiveness, the British are surely leading the way. Does any other nation become quite so clammy and over-excited when professional tennis players arrive to play a tournament? For the two weeks of Wimbledon, looking up women's skirts – a habit normally the subject of social disapproval – becomes a national pastime, the subject of wet-lipped debate, illustrated endlessly in the press by photographs of female tennis players' bottoms.

Unsurprisingly, the less balanced members of the community are whipped up into a dangerous state of excitement by the underwear question: no less than eight stalkers have been banned from visiting the tournament this year – and they are just the ones known to the police.

It is surely odd that normally respectable newspapers devote pages to discussing whether an attractive female tennis player, tired of being ogled by sexually frustrated Britons, was right to wear shorts, or that the red-tops should compete to get the most revealing pants shot, or "up skirts" as they are known in the pornography business. The British, though, seem to regard all this as entirely normal.

So when a man in his fifties takes his shirt off to show his muscles to a class, there are gasps of outrage, but when other men gather in south-west London to look at and photograph young girls in their knickers, it is good old-fashioned fun.

A weird and not entirely healthy act of psychological transference seems to be taking place. By interpreting innocent acts, whether taking off a shirt or playing tennis, as erotic, the prudes and pervs of today are revealing their own sexual restiveness.

Nelson's celebrity riddle

As Nelson Mandela smiles his sweet smile at today's Hyde Park concert to celebrate his 90th birthday, he might also be pondering the pros and cons of playing the celebrity game. The Sugababes, Queen and Leona Lewis will be doing their stuff on stage, but their number will not include another famous Mandela fan, Naomi Campbell.

The problem is that Campbell was wearing a baseball cap bearing the number 46664 – once Mandela's prison number, now a logo for his anti-Aids campaign – while attacking police officers at Heathrow. The supermodel's infuriated resistance to authority is a long, long way from Robben Island, but offers its own little moral: endorsements by celebrities can sometimes backfire.

* Even after 11 years, it is difficult not to be faintly shocked when a Labour minister, explaining an unfair government policy, invokes market forces as justification. The very people who once loathed the cold brutalities of Thatcherite economics are now deploying identical arguments.

Explaining why BT is allowed to charge prisoners eight times the going rate to make a telephone call to keep in touch with their families, Maria Eagle came up with a near-perfect piece of New Labour jargon. "Prices are benchmarked against market conditions," she said.

Unscrambled, this means that market conditions excuse anything and everything. Using financial means to remove the lifeline of those unable to see their families is perfectly acceptable. Increasing the likelihood of mental illness, suicide or re-offending is a price worth paying, if the shareholder dividends are healthy. Ms Eagle is – please don't laugh – Minister for Justice.

terblacker@aol.com