For Fabio Capello, this must have come as the kind of punch to the psychic solar plexus to send a weedier chap to bed with a a quart of Scotch, a bottle of tranquillisers and a mobile phone with the Samaritans on speed dial (if not the girlfriend of a third- or fourth-choice England full back).

Don Fabio is a right old bruiser, of course, and less likely than most to be cowed by the fearsome moral philosophers of the media. Even so, coming from a country in which the notion of a leader cheating on the mother of his children is too surreal for words... well, let's call it a paralysing culture shock to any Italian, and leave it at that.

Once the paralysis fades, Capello, who worked for Silvio Berlusconi in many capacities over many years, will have a decision to take. Now that John Terry has frontally challenged the received wisdom that Premier League footballers are sport's answer to the Methodist laity, can he remain as England captain? This question has obsessed us for days, and rightly so. It is impossible to overstate the significance of the captaincy as a great office of state from which the incumbent is traditionally expected to set a behavioural example to the rest of us.

A glance at recent history confirms this. Among those splendid role models to wear the armband during the last 15 years are Tony Adams (did porridge for driving into a wall when blotto), Alan Shearer (retained captaincy after being filmed viciously kicking an opponent in the face), Michael Owen (likes a gamble), Gary Lineker and David Beckham (neither fabled for carnal fidelity, the latter enjoying a fling with a woman best known since for manually pleasuring a pig).

Mr Terry has flirted with several of the disciplines mentioned above. It was in drink that he joined team-mates in taunting American tourists about 9/11 a few days after it happened, and he was later acquitted of various offences arising from injuries sustained by a nightclub bouncer. He likes a bet, waltzing into a Coral's in Surrey one afternoon with a friend and team-mate, one Wayne Bridge, to blow £13,000 in a few hours. And among his many headline appearances was a star turn in The Sun for allegedly inviting a teenaged autograph-hunter into the back of his Bentley, and she said giving her rather more than his hand.

Only after the above had become public knowledge did Signor Capello's predecessor appoint him captain. "I'm certain I've got the right man in John Terry," said Steve McClaren in August 2006, and as so often, Old Beetroot Face was spot on there. So resolutely has Mr Terry maintained his commitment to filling newspapers (with sterling support from the shoplifting mother, and the father collared recently for pushing cocaine) that he is a 2-7 chance with that same Coral's to receive a Lifetime Achievement Award at the British Press Awards ("the Oscars of our industry") in March.

The latest tour de force, a few Sundays ago, concerned the flogging of a guided tour of Chelsea's training facilities for £10,000. His cut was headed for a children's charity, he later insisted, and given his status as celebrity Dad of the Year, as elected by admirers of Daddies brown sauce, it wouldn't do to be sceptical about that piety.

Boozer, gambler, cuckolder, self-pimping money-grubbing general all-round horror... if the England captain's duties involve representing the essence of his sport, you'd have to write your own software and make a breakthrough in hologram technology to invent a character better suited than John Terry. But they don't. The oddity about this superheated captaincy debate is that its only real duty is carrying a pennant. Entirely honorific, this is the sporting world's tribute to the regimental goat.

If England regained the Ashes largely because of Andrew Strauss's tactical nous, and won the 2003 rugby union World Cup thanks in part to Martin Johnson's stirring oratory, can you recall anyone ever using the captaincy to influence a football match? Casting the mind back over the 44 years of hurt since Bobby Moore wiped the dirt off his hands to spare Her Majesty's glove, I can't think of a single example. And I suffer from an obsessive, all-consuming nerdiness about such things that places me at the Asperger's end of the spautistic spectrum.

Mr Terry would be as impressive a yeoman leader of a back four with or without the armband. The fact that the victim of this indelicacy, that erstwhile betting-shop buddy Mr Bridge, was a Chelsea colleague then is as irrelevant, given the unlikelihood of him being picked for England now, as the captaincy itself.

If football was our society's version of Camelot, it might be otherwise. When Lancelot cuckolded Arthur by slipping Guinevere a chivalric length, this was a catastrophic betrayal of the dominant honour code of the age. When Mr Terry enjoyed his twice weekly sessions with Vanessa Perroncel, he was rigidly upholding the code of dishonour – the one that says that being young, wealthy and worshipped infers absolute entitlement to instant gratification of every kind – that governs football.

Are we to punish a man for obeying the mores of the society in which he is a leader? Is a man to be pilloried and despised, let alone humiliated with the sack, for doing what all leaders are expected to do, and personifying the prevailing ethos of his world?

It's fine calling it the beautiful game while watching a DVD of Pelé, Carlos Alberto, Jairzinho and the gang winning the World Cup not long after the England captain of the time was arrested on suspicion of stealing from a hotel jewellery store. But that was Brazil, and that was then. If you survey English football today, it is a buoyantly venal, mercenary and corrupt game staffed at playing level by drinkers and shaggers, braggarts and bullies, cheats and thugs. It is thoroughly amoral both on the pitch, where uniquely in sport the weaker team frequently beats the stronger, and off it. Any passing human rights violator with a few hundred million can sail through the "fit and proper persons test," and we fans are little better. "I couldn't care less about the human rights," as one otherwise impeccably liberal Manchester City fan put it when Thaksin Shinawatra arrived from Thailand, "if he can get us mid-table respectability."

If England lead Argentina in the last minute of a World Cup quarter-final this summer, not one of us this side of the border would object if John Terry prevented Lionel Messi from equalising by slicing his head off with a scimitar (so long as the blade connected outside the box). In the unlikely event of Hitler coming off the England bench and winning the Jules Rimet trophy with a 30-yarder off the underside of the bar, renditions of "Walking in a Führer Wonderland" would resound through the football-loving homes of Golders Green and Stanmore Hill.

All in all, then, the sooner this unwonted ascent of the moral high ground is reversed, the sooner the altitude sickness behind this curious hallucination that the England captaincy is a bully pulpit for conventional morality will go away. Once his own ague has faded, Don Fabio would do well to hold his nerve, shrug a Berlusconian shrug at all the fuss, and leave his regimental goat tethered to the armband.