Congratulations, you're a politician. You have beaten off all comers, by dint of hard foot-slogging, attending to the doorsteps, attending a thousand basket suppers, schmoozing old ladies and angry householders with a grievance, forgetting about sleep as you leap out of bed to get your 30 seconds of glory on Morning Ireland - the prize is won.

So now life becomes constituency clinics, debates in the Oireachtas, committee meetings, strategy meetings with your advisers, briefings from interest groups on important issues, research in the library, more basket suppers, and, perhaps, a few hours for your loved ones or a walk on the beach, just now and then.

Should the Hottest Thing Since Tabasco suddenly come into your life, throwing itself into your arms like a rocket, how on earth would you schedule in an affair?

Yet, as the alleged amorous adventures of the British Foreign Secretary, Robin Cook, have shown us yet again, some individuals seem to thrive on the illicit dalliance as much as the buzz of the power democratic government confers.

Mr Cook, under that tide of tabloid pressure so familiar to his predecessors in power at Westminster, the sleaze-entangled Tories, announced on Sunday night that he is to divorce his wife of 28 years, Margaret, and marry his secretary, Gaynor Regan. This profound change was announced on the hoof, as Mr Cook arrived at Edinburgh airport for a meeting of his Livingston constituency. With Ms Regan, a decade his junior, at his side, the diminutive Mr Cook made a Duke-of-Windsor-like declaration of "the woman I love" variety, announcing that he would make Ms Regan an honest woman as soon as he had freed himself from the legal bond with Margaret, a consultant haematologist at an Edinburgh hospital.

The Sunday papers that day had enjoyed themselves at Mr Cook's expense with reams of newsprint about his hinted infidelities other than Ms Regan. The supposedly more "serious" papers raised the awful spectre for the ambitious Mr Cook, that he might have to resign over his extramarital past. The Daily Telegraph, in an editorial on Monday, raised the old chestnut that "if a man cannot be true to his wife, he cannot be true to his country", before generously going on to concede that he should feel no obligation to resign.

But Rockin' Robin is just the latest in a long line of political serial infideles, the most famous of our time being John Fitzgerald Kennedy, whose history of back-pain never seemed to stop the other parts of his body doing what came naturally and doing it plenty. JFK is reputed to have told one political peer that he had a serious physical need for sex several times a day, and would be ill without it. The stories of princesses and showgirls being ushered discreetly into the White House, hotel rooms and family residences along America's east coast, are legion, repeated and fleshed out again in Seymour Hersh's recent, controversial book. And all the while the personable former senator for Massachusetts was juggling the Cuban missile crisis, relations with the Soviet Union at the height of the Cold War, and the time bombs of both the Mob and the US civil rights movement.

And did JFK not have one of the most attractive and elegant women in America as his consort? One is reminded of the astonishment of the trial judge when politician and novelist Jeffrey Archer sued for libel over allegations that he had attempted to pay off a callgirl. Misty-eyed, the learned judge expressed his disbelief that any man with the excellent fortune to be possessed of so intelligent and beautiful a wife as the "fragrant" Mary Archer would ever stray.

But men - and particularly men in power - do. From Henry VIII to John Profumo, many leading political figures find that variety is the spice of life. Is it a need for continual approval and acclaim, or to establish mastery, in the bed if not in the country, or just an insatiable thirst for non-stop stimulation and excitement?

Is it the case that those who go on to have second families do so because they think their genes so super-special that they should be passed on again, and again? Or, after having put in a 25-hour day doing the rounds of international diplomacy, party infighting, constituency crises and keeping the media at bay, do they simply feel they deserve a little bit of an extra reward; that they have earned the right to let off more steam than the average worker?

Professionals in the field of human behaviour say the answer lies within, and is most likely rooted in an individual's relationship with himself. Dr Harry Ferguson, lecturer in sociology at University College Cork, says there are elements of both a desire for power and chronic insecurity in what is known as the "Casanova complex".

"There are sometimes deficits with men in terms of getting their esteem in the public domain," he says. "Their traditional socialisation has taught them not to prioritise intimate relationships. But when these relationships fail, they have to confront their inner demons, perhaps an inability to sustain satisfactory relationships, and this often leads to bouts of depression."

Mary Mulcahy of the Marriage and Relationship Counselling Service in Dublin also sees insecurity, no matter how well hidden, at the base of the serial affair syndrome.

"In this situation it is usually a person who does not love themselves who strays," Ms Mulcahy says. "It is a narcissistic thing. They think they have found a mirror to reflect how wonderful they are, but after a while, because that mirror says they are wonderful, it must be valueless itself. They don't really believe they are wonderful, and this lack of self-worth goes back to early infancy."

She points out that rich and successful people are not the only ones to have affairs, but "it isn't easy to have a series of affairs unless you have plenty of money and people assisting you".

Now I wouldn't want anyone to think that I, a woman, am pointing the finger at men as monopolists of this form of social misbehaviour. But the truth of the matter is that it is very difficult to think of any woman, at least in contemporary times, who has been notorious for sexual frolics. Former British MP Edwina Currie did make some comment recently that suggested her appetites are healthy, but apart from that this seems to be one area which women either stay away from, or make sure nobody knows about if they are in fact indulging. There was no talk of sleaze in the Margaret Thatcher household.

Ms Mulcahy of the MRCS refers to Marilyn Monroe as one famous and successful woman who continually sought affirmation through a series of marriages and affairs with successful men. "The poor girl - it looked like she had everything and yet she was trying to prove herself all the time."

And how is it that in England all this causes such a brouhaha? Here, with many senior politicians in various forms of second relationships, some formalised, some not, it's one area that rarely reaches fever pitch. What in Britain are often portrayed as "affairs" are treated by and large as relationships on this side of the pond. No doubt, the ferocity of Irish libel laws is in some cases a factor.