There is, I suppose, the matter of judgement - surely that lets me off the hook. I mean, imagine for one moment that you are a balding, relatively undistinguished Tory MP in his late forties. Over the past five years you have watched horrified as - one by one - your colleagues have fallen victim to tabloid revelations about their sexual peccadilloes. And then, out of the blue, a voluptuous teenage blonde blows into your life, and makes it wonderfully clear that every sad middle-aged male fantasy you've ever had now stands on the verge of realisation. What are you to make of this emanation?
Explanation A is simple - it's a set-up. Explanation B, however, is rather more incredible, for it involves a young girl thumbing through her Soho dive's copy of The Parliamentary Companion, stopping at your unremarkable snapshot with a cry of excitement, and telling herself that this is the guy for her. To believe Explanation B you need only one qualification: you need to be a cretin. And we do not want cretins in Parliament now, do we?
This excuse will not wash either, for it is the universal human dimension of the thing that engages me, not the involvement of a public person in it. Like the pathetic way in which Mr M has tried to explain away the incriminating photographs and timetables. "You must have a weird sense of values if you see anything wrong with me kissing a girl in the park," he told The Sun. It is indeed possible that Piers treats everybody to this kind of internal lavage. He even snogs his wife this way, as he demonstrated gruesomely on Thursday.
But what about Tuesday night in Pimlico? Anna had been photographed going into Merchant's London flat at 10.45pm - and coming out again at 9.45am the next day. Yes, agreed Merchant, "Anna called at my flat that evening, but she did not stay the night." Since the MP himself agreed that there was no back entrance, we are forced to surmise that the young lady made her way out over the roof sometime after 11pm, and then clambered back the same way before 9am. What will his association make of this account, one wonders?
But the thing I like best in these stories is the extraordinary language in which the ratting mistress tells her tale. Anna Cox, for instance, recounts an early indiscreet bout of snogging in the very centre of London. "It seemed like a dream," she gushed, "to have a real-life MP almost making love to me in Trafalgar Square. His hands went up my skirt." Eh? One moment we are in the middle of a Nancy Friday revelation, and the next the poetry of fantasy has been replaced by the prose of sex. This is typical.
Semioticians and media students will also enjoy the constant repetition of a particular theme in the Cox tale. Always she "senses" things; things which one might expect rather to be seen or felt than sensed.
Try these: "I could tell he was aroused by the sexy atmosphere between us"; "I could sense electricity between us"; "I felt his hands on my legs and sensed his excitement when he reached my stocking tops"; "I felt he was about to try and have sex with me"; and - my personal favourite, which proves that she is not (as I was beginning to suspect) suffering from impaired vision - "I have never known anyone get so excited as Piers. His body is thin and quite weedy."
This magnificent and mind-bending non sequitur is as nothing, however, when compared to her account of what eventually happened in the park. "I'm sure he wanted me to go all the way," said the scrupulous Ms Cox, "but I couldn't bring myself to to do it in the middle of the park. I ended up performing a sex act upon him."
There we have it: the stuff of tabloid scandal - "I sensed his mounting excitement, so I performed a sex act upon him"; a Joan Collins novel as ghosted by a police sergeant. Tawdry isn't the word.