I attended the Piers Gaveston Society in the mid-1980s, when I was at Oxford in the year above David Cameron. The parties were debauched and tremendous fun. But Dave was not there.

The most remarkable figure at the heart of the Gaveston was Gottfried von-Bismarck, the Iron Chancellor’s great-great-grandson who, after his untimely death at just 44 in 2007, was said by the Telegraph to have led an ‘exotic life of gilded aimlessness’. The paper’s beautifully written obituary almost paid tribute to this ‘louche German aristocrat with a multifaceted history as a pleasure-seeking heroin addict, hell-raising alcoholic, flamboyant waster and reckless and extravagant host of homosexual orgies…’ I did not ever know Goffried well or see him in full throttle, but he was clearly on a mission.

My friend Marcus Edwards-Jones, who in those days was one of the Piers Gaveston’s select few members, whereas I was an occasional guest, says, ‘I remember meeting you sporting fishnets, a jockstrap and not much else except for make-up at a Gaveston do in 1986, but don’t remember Dave being there.’

I clearly recall the only reason for me wearing drag was that I had come straight from playing the role of Frank N. Furter out of The Rocky Horror Show in a variety show at my college, Balliol. My only performance ever as a transvestite had been a big hit, so I kept the kit on for a while because it made people laugh.

The party that spring was in the castellated brick house over the Isis on Folly Bridge, the one decorated with the little white statues. There were lots of attractive women, who were the focus of my interest, and Gott-fried, who I’d met some months before, had rather hopefully covered the furniture and floors with polythene. It was a thrilling evening for a 20-year-old — though the goings-on were nothing compared with some parties that I and many of you have seen as proper adults. Cameron was not there — and there were definitely no pigs.

Marcus suggests the pig’s head story originates from ‘after 1985 finals, when Ollie Channon and Gottfried impaled some pigs’ heads, procured from the Covered Market butcher, on the spikes of the railings in Oriel Square, as part of the celebrations…’ He adds sagely: ‘I don’t recall any necro-bestial action, and this was the term before Dave went up.’

In those days, pigs’ heads from the Covered Market were a favourite as props for undergraduate high jinks — and probably they still are. I don’t know why. Gottfried placed pigs’ heads at either end of the table at his riotous dinner parties. At a May Eve celebration I, together with my friends Jeffrey Lee and Steve Micalef (the king of punk at Oxford in our generation), found a pig’s head near All Souls, which we wheeled around in a supermarket trolley to all the parties we could crash until dawn came up with the Morris dancers and singing at Magdalen College.

Why, I even recall how Tributary, the satirical magazine I co–edited, fondly dubbed the president of the Oxford Union, Boris Johnson, ‘the Aryan Bull Pig’. Trib, as our rag was sometimes known, also ran a photo, which I still have buried somewhere, of Gottfried in a turban at one of our magazine parties, with the caption ‘Otto gets Blotto’.

Overall, the Cameron pig story just doesn’t ring true. The Piers Gaveston was too libertarian and eccentric for him. We were not interested in the Brideshead Revisited stuff. And we never saw Cameron. I think his place was more usually at the Oxford Union bar after debates with the Young Conservatives, ‘dicking the air’, as Toby Young so wonderfully described that groin thrust that only men in corduroy trousers can achieve.

Regarding pigs’ heads, as Marcus so rightly says, ‘We Gaveston men preferred our consorts to have a pulse at least.’ He adds, pooh-poohingly, ‘Dave never attended any of the Gaveston reunion do’s.’ (Cripes, I thought — what goes on at the Gaveston reunions?)

This pig’s head thing might have happened elsewhere — at the Bullingdon, perhaps. My usual circle did not have much to do with the Bullingdon, though some members were friends. One dear pal of mine at a nearby college was absolutely terrified when the Bullingdon wished for him to join and came to ‘trash’ his room, a sort of hazing ceremony to initiate new members. My friend, a scholarly and private man, but also an aristocratic sort, had no intention of ever enrolling in the club.

The youths in all their finery bashed down his door with loud huzzahs and were just setting about ‘trashing’ his room when, to their terror and astonishment, he charged at them with a claw hammer. Wielding this, my friend rained blows down upon their backs as they ran for their lives, pursuing them down the winding stairs, across the quad and out of the gates, yelling abuse in the strange Elizabethan English he often used.

My encounter with the Piers Gaveston was necessarily brief, because Gottfried’s dear friend Olivia Channon died of excess during their celebrations at the end of their finals in 1986. It was tragic because Olivia was such a lovely person, and in the ghastly fallout that occurred after that, the lights went out on a lot of the partying and debauchery. I doubt if the Piers Gaveston even met at all for a year or two, which would have covered the rest of the time Cameron was up at Oxford. I’ve spoken to people who attended the Piers Gaveston more recently and the events sound pretty dull. As for me, I moved on and I haven’t ever done anything with a pig’s head since.