The distinction between who is and isn't fair game for the press is complicated. So it is a relief that we can all agree on Sir Fred Goodwin. Actors and footballers are one thing: a hubristic banker who left the taxpayer with the bill for his rampage is a different matter. We can tell that the alleged affair between Goodwin and a senior colleague at the Royal Bank of Scotland is a solid-gold scandal rather than diverting gossip because the Financial Services Authority has deemed it worthy enough of investigation.
The case for the prosecution is that it coincided with the collapse of the bank in 2008, and thus may have had a bearing on it. Was Goodwin so pumped up with pheromones that he turned like a "rutting chimpanzee" (as Dominique Strauss-Kahn has been described) on the Dutch bank ABN Amro?
I am as delighted as the next taxpayer to see Fred Goodwin discomfited, but the evidence that sex causes professional lunacy is not watertight. One could as easily argue the exact opposite. If the anonymous colleague had not divested Goodwin of some of his energy, he might have fastened on to an Icelandic bank as his next acquisition. Ever since Goodwin took on NatWest in 2000, there were murmurs about his "throbbing ambition" and thirst for "leveraged buy outs". It may be that his colleague was performing a public service by encouraging a different definition of Goodwin's famous "five-second rule".
The blurring of professional and sexual performance met its logical conclusion in last week's revelations that a German insurance firm had rewarded its most highly motivated salesmen with an orgy at a thermal bath in Budapest. The prostitutes hired for the event paid tribute to north European tidiness by wearing colour-coded bands and stamps that listed the hierarchy of their services.
The connection between Goodwin's gigantic bank deals and his affair is an appetite for calculated risk and we can infer from all these cases a coupling of sexual reward with professional effort.
One would have to be a very confident behavioural psychologist to measure the influence of sexual behaviour on achievement in the workplace, though. Men, traditionally, are less emotional about sex than women. The best book I have read on affairs at work is Lucy Kellaway's novel, In Office Hours. It is her female character who becomes unhinged by a relationship with a younger, junior colleague. Men have had years of training in taking it in their stride.
I doubt very much that Fred Goodwin's judgement was impaired by his affair. The fault with his judgement was his judgement.
The case against adultery, I think, is the betrayal of trust. Great recent leaders – Tony Blair, David Cameron, Barack Obama – appear to have strong relationships with their wives. Uxoriousness is a political as well as a domestic advantage. It is sorting out the plausible candidates from the goats for the next American presidential election.
At its best, marriage is a moral compass. Chris Huhne has been adrift ever since he turned his back on the institution. But these are personal misfortunes, of debatable public interest. Goodwin's affair is a matter for his wife. It is his disgraceful stewardship of a great bank that I want to punish him for.
Sarah Sands is deputy editor of the 'London Evening Standard'