"Is your partner suddenly available at different or unusual times, and unavailable at times when previously she was with you?" "Does he avoid certain places, like particular restaurants?" Increased sex drive is a sign, as is a declining sex drive. Or, my favourite: "Is there a new odour signature?" Make of that what you will.In Biblical times, tell-tale signs included your husband sitting on the palace roof spying on Bathsheba bathing, or (if you were unlucky enough to be called Uriah the Hittite and Bathsheba was your other half) finding yourself suddenly sent to the bit of a battle where the most smiting was going on.Today it's easier. Had he travelled alone wearing dark glasses and a frock, stayed in a single room at a seedy pension, disappeared each evening by Lambretta and been seen in cafes playing chess with septuagenarian male amputees - then we would have known that something was up.This is why all the books and magazines that offer advice either on detecting adultery, or (in these wicked times) on how to commit it, lay the stress on normality - discovering deviance from it, or maintaining the veneer of it. Nice work if you can get it, but hardly James Bond.The day after the story appeared, Allason's insouciance was explained when he revealed that actually he had split up with the wife a couple of years earlier, at which the newspaper that had been following him tried, rather bizarrely, to suggest that in fact they were still a devoted and happily married couple ("New Twist To Allason Affair").What, of course, gave Allason away as not really being a love cheat was the entire absence of deception.

I thought it was all a bit too easy. Yesterday's tabloid revelations concerning the visit a deux to St Tropez by the Conservative MP Rupert Allason and a winsome violinist seemed to have involved remarkably little effort on the part of the crusading journalists who penned them Strangely, Mr Allason did very little to escape detection. Events seem to have unfolded thus: Mr Allason went straight from losing a malicious falsehood case against a newspaper in the High Court, changed into Rich Author's Casuals (stonewashed jeans, jumper draped over shoulders), drove to the airport, flung his arms around the fair fiddler, sat next to her on a plane, took a taxi to a "hotel love nest", went on the beach (where she took her top off), read a spy novel or two, and then came home with her. Such behaviour required his intrepid stalkers to sort of follow him about, take lots of unobstructed pictures (including the obligatory empty bed) with an ordinary lens, and occupy a neighbouring lounger on the beach while pretending to read a Jackie Collins. Are barracks bedrooms, sleeping quarters below decks, public spaces for this purpose? Yes they are: liberal rules of entry apply; but once inside, institutional rules of conduct hold and they may well restrict the scope for "difference".Individualism has not run its course. Classes and groups may still justifiably claim discrimination and obstruction in their access to the public spaces of our society But those spaces are not playgrounds In them, strict rules of conduct legitimately apply. In them, formal equality may require us to look and behave the same..