Christian Institute screengrabYou might think that if one Queen is good, two would be better; but such a situation would offend the British sense of fair play. Imagine how easily we would crush our opponents at war; our two powerful amazons scattering helpless pawns in their wake, enemy knights struggling to find anything to checkmate as their puny king crawls miserably, square-by-square, toward his inevitable doom. Does that sound like cricket to you?

Not according to Peter Bone, a Tory MP who apparently lies awake in bed at night bathed in sweat at the prospect of lesbian Queens. Bone has come up with the ultimate rational argument against gay marriage – if we allow it, we might end up with a pair of Queens.

How could the monarchy possibly survive? From Anne Boleyn to Wallis Simpson, the Royal Family is an institution built on the solid bedrock of traditional marriage. Henry VIII thought it so important he wedded six times, while the more recent romance between Charles and Diana will inspire countless generations of fairy-tale writers to come. Monarchy and marriage are terminally intertwined; like a snake and a crocodile trying to eat each other.

An even more compelling reason to block gay marriage is the argument that if you let men marry men, then there’s nothing to stop them marrying lots of men, or children, or even items of furniture. It’s such a powerful line of reasoning that the Coalition for Marriage – cunningly named after two institutions whose popularity is in decline – used it on the front page of their “pro-marriage” petition. My response to this on my Guardian blog was to ask C4M: “What’s wrong with polygamy?”

This went down less well than I expected, and ever since I’ve been the Christian Institute’s poster child for polygamy. I am a living, breathing example of the sort of moral decay infesting modern Britain, sitting in my pants, swigging beer and egging on the rampaging armies of militant gays and secularists laying waste to good old national traditions like workhouse labour, sneering at neighbours and beating up “the darkies”.

Every new argument against gay marriage sounds like an increasingly desperate attempt at post hoc rationalisation for a pre-existing view. We’re told that marriage shouldn’t be defined by the state, but it already is. We’re told that marriage is traditional, but we don’t have any problem getting rid of bad traditions. We’re told that marriage should be about procreation, but for many married couples it isn’t, and if opponents of gay marriage are that worried about the kids then why aren’t they doing more to prevent “unsuitable” heterosexual couples from marrying too?

The reality is that there is one, and only one, real reason to oppose gay marriage. All other arguments are a convenient smokescreen, a series of snivelling excuses from curtain-twitching cowards who don’t have the guts to stand up and admit to the bigotry that forms the foundation of their so-called morality. That reason is homophobia, and we should be ashamed that in 2012 it is still so widespread in our society.