Every wicked pleasure requires a pious justification. It was, of course, wrong for the husband of Jacqui Smith to include the bill for watching four films (one of them twice) among her expenses. But all headlines, from the loftiest broadcasting organ to the inky guttersnipes of far tabloidism, have concentrated on the “adult” movies supposedly consumed by Richard Timney, and have relegated Surf's Up and Ocean's Thirteen to the small print, although they (a) cost more and (b) are, I imagine, just as inadmissible as Raw Meat 3 and whatever else it was that investigative journalists have subsequently discovered was on offer through Virgin (sic) on the nights in question.

One response to Ms Smith's hideous embarrassment was a delighted priggishness. Naturally no male journalist could be found to admit that he too had watched pay-movie porn. Just as naturally, no male I have spoken to about this privately, has not watched it. Well, I certainly have.

So it was with a slightly wry smile that I read the reactions of another Home Secretary's spouse, Sandra Howard, published yesterday. “Seeing [Mr Timney's] private indulgence portrayed in such a devastatingly public way obviously undermines the very essence of a bond of trust,” she said. “It would be enough that she overlook his porn habit, but to skewer her career by allowing it to become publicly funded is harder to forgive.”

I don't imagine that she knows Mr Timney that well, but how can she deduce from the purchase of two adult movies that he has a “porn habit”? And if two blue films a porn addict makes, has she considered that she may be practically surrounded by porn addicts?

Good statistics are hard to come by in this field, but a survey conducted by the Mormon-owned Brigham Young University in 2007 questioned students about their experience of pornography. During the past 12 months, they were asked, on how many days had they viewed pornographic material?

Only 13.9 per cent of the men said that they hadn't, so I sometimes think that women are in a mild state of denial about the blokes they mix with. Another statistic, which I can't vouch for, is that the average hotel porn movie is viewed for only 12 minutes. That may surprise women less.

So the very aspect of this that has caused so much censorious joy is the very aspect that is most universal. That is one element of the hypocrisy. News outlets have described the situation as “humiliating” to the Home Secretary and done their best to make sure that the word is apposite. That's the other.

Let me insert right here my belief that claiming to the max and beyond is an unlovely trait, albeit one that most media folk aged over 45 remember with fondness when in their cups. But my guess - no better and no worse than anyone else's - is that there was no real intention of getting the taxpayer to pay for the movies, but that they were included in the middle of a bill that covered several claimable items.

It has been said before, but I also think that the origin of the expenses problem lies in the fact that, relative to other legislatures, our MPs are underpaid. All those that I know work preposterous hours, and the most able would be paid and treated far better in other jobs.

The issue is not one of fairness, however, but the practical one of not dissuading good people from running for office, so I would like to see 150 fewer MPs each paid considerably more and with much better resourced offices both in Westminster and their constituencies.

But many commentaries are written on that subject, and almost none on this - which is that the Smith affair seems to me to be as much about our punitive and hypocritical public culture as about expenses.

No one, for example, even in a month of database and Google Street anxiety, seems at all concerned about the privacy element in all this. In newspapers, on television and computer screens we, in our millions, have been shown copies of the bill in question - someone else's bill - itemising the times and dates of the films. In terms of exposure of personal data it is as big a breach as one can imagine, and one designed specifically to “get” the Home Secretary. Nor do I think, as many do, that the morality is covered by the rubric of “it's public money, we should know how every penny is spent”. I cannot see why it would be insufficient if the Commons authorities simply refused to pay the bill, explaining why to the claimant. That's what I would expect any good employer, such as The Times to do, or - if the issue is taxpayer's dosh - the BBC.

There has been some speculation about exactly how the Sunday Express got hold of these documents. The more romantic imagine a heroic but disgusted whistleblower in the Commons; the more conspiracist picture a Tory mole like the one who fed Damian Green. But one suggestion doing the rounds is that all expenses submitted by MPs and scanned by the relevant office have been placed on CDs and touted around the media for sale, either in batches or as a whole - meaning that the “blackout” of expense details is already too late. I predict that we are about to see more of Plod working the Gothic corridors.

The implications are unpleasant. Such an outcome would mean that there was an organised scam, probably involving one or more public servants, based on the calculation that there existed a lucrative market for this kind of stolen information. That market would exist, in part, precisely because the media and the public would always find something to condemn in what MPs (or other public figures) were getting up to. If that's the case - and I believe it is - it means that our stinking prurience has bought the subornation of public servants, and that is far more serious than 21 quids' worth of movies.

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