On 22 June 1822, Alexis St John, an employee of the American Fur Company on Mackinac Island, was accidentally shot in the stomach by a colleague. He was treated by Dr William Beaumont and, against all the odds, survived. He was left, however, with a hole in his stomach that thereafter provided Beaumont with a unique insight into the workings of the digestive system.

A terrible accident. An almost mortal blow. Recovery and the snatching by another of the chance to peer with a fascination tinged with revulsion at a world customarily hidden from us . . . I cannot tell you how closely the story of St John and Beaumont parallels my own experience, over the last six years, of falling in love with a man, discovering he was a Tory and then learning to live with his depraved political inclinations.

Why do people become Tories? Radioactive scorpion bites? DNA spliced with weasels? An overwhelming psychosexual urge to do unto Britain what the physical appearance of most of them suggests was not done unto them by even the kindest-hearted local girls as adolescents (a period for Tories generally extending into their mid-40s)? As a state-school-educated child born of parents working in the theatre and the NHS during the 80s, I hadn't even met a Tory until I went to university. But even then, housed as we were in one, essentially leftwing institution, their political tastes amounted to the 90s version of the love that dared not speak its name, and were accordingly kept more or less private. I never found out what made them tick.

Now that I live with one, there are more opportunities to perform the equivalent of Beaumont's experiments. The doctor used to dangle bits of food on string into St John's gastric gap and retrieve them hours later to see what had happened in the interim. When it comes to sourcing evidence of the Tory psyche's corrosive workings, I have it easier. I have only to switch on the television, and rage at the BBC's liberal bias fills the room. We have friends round for dinner and end up feeding them slaughtered, sacred cow – last weekend it was the "bloated, Byzantine bureaucratic nightmare that is the NHS. It doesn't work, people are always complaining about it and one day you are going to realise that you can infer something from that." Please don't strain yourselves writing in. I promise you can trust to me and mine to make the necessary stands. I open my daily newspaper and it gets torn to shreds metaphorically, its "utter hypocrisy in condemning the intolerances of others as if there were something, anything in this world more rigid than the liberal orthodoxy" (to quote from Monday's breakfast rant) or "regard for the environment that would have made Hitler stop and ponder whether this blend of anti-human, self-praising crypto-paganism hadn't gone too far" (yesterday) overwhelming him, literally.

When I caught and managed to question him in a calm and Berliner-free environment on the matter, Toryboy had this to say about the roots of his Conservatism: "We are people too. Different people, different even unto each other, even when we're closely related, identically dressed and intimately familiar with one another since college, but people nonetheless. Not shape-shifting Doctor Who-reject aliens bent on destroying good, enslaving joy and mastering the fox – and claiming the last to be a 'civil liberties' issue. People. But we are people who believe in freedom. Freedom to do things, to not do things, to not have things done to them, to not have to do things for other people. CCTV, seatbelts, child-proof caps on the Nurofen, even fighting the white line in the middle of the road can all be part of the agenda of freedom, and reasons for being a Tory. At the same time, sometimes even in exactly the same mind, it's the permissive society, and excess licence, and horror at widespread societal disregard for the rules and common decencies that propels one towards the blue. Sometimes it's ideological commitment to the abstractions of the free market, other times it's an almost neo-feudal regard for tradition. If you could set aside your progressive bigotry for a moment, you would see that it is our very openness that gives us our huge advantage over Labour: in the house of the right, there are many mansions. In every sense of course, but we'll leave the class issue for another day. Channel 4 news has started and I've got to go and shout at that Trot Jon Snow."

It occurs to me suddenly that the St John-Beaumont story would have suited our purposes even better if it had involved the spleen.

Conference week is – however counterintuitively – a relatively relaxing time in our household. A rabid anti-Cameroonian, Toryboy's ire is, for five blissful days, directed exactly where it should be – at the Tory party, who are apparently currently holed up in Manchester "only so that Cameron and the rest of his shiny-faced, non-boat-rocking, daily-blogging, Google-worshipping, braces-wearing, common-sense-solution-supporting, gently salivating crew can say they've been to the north".

It is this that gives me hope that the real roots of Toryboy's Conservatism lie not in an early consideration of all the options and rational choice in the one with whose policies he best agreed, but in something deeper. I want to – no, I have to – believe that it is his love of the past (he is a historian by inclination and training) that has really led him to identify with the most backward-looking party/party fondest of tradition, coupled with his natural tendency for contrarianism. If, when he and I were growing up, Labour had been the reviled party in power, perhaps he would have cleaved to them instead. I'll dip that morsel of thought in and retrieve it later. We'll see if he's got any bile left in his system after shouting at Jon Snow.

If Cameron does get in, it will be interesting to see what Toryboy does. Will he join Labour in protest? Will he retreat into hardcore Thatcherism, or will I find him rocking gently in the corner of his study and murmuring fond anecdotes about Lord Salisbury? Maybe I'll finally get an answer to the question that has plagued me this last half-decade and more – is he mad, bad or just interesting to know?