Charlotte Edwardes’s allegation that Boris Johnson once groped her thigh has divided the nation, like everything always does nowadays. Johnson denies the claim but that’s not what caused the divide. In fact, that’s brought people together because no one believes him. I reckon, to put a very conservative estimate on it, absolutely everyone believes her. People think he did it because it’s so obviously the kind of thing he’d do. He may not remember the occasion but his interior monologue is bound to be saying: “Yeah, that sounds like me.” He might as well deny having once sneezed.

Obviously it is possible, though I’d say unlikely, that this specific event did not occur. But, unless you happen to be Charlotte Edwardes or someone who’s close to her, that doesn’t massively matter. With so many of his actions, Johnson has for years been proclaiming himself the sort of man who probably gropes women, so, to my mind, the only real question is whether the name of one of the women he has groped is Charlotte Edwardes.

Yet this groping story gives a fascinating insight into the prime minister’s philandering MO. He’s long been a busy, successful man – how does he have time for all the affairs and fathering of illegitimate children, one wonders. Well it turns out he’s an amazing multitasker!

Picture the scene: there he is, running the Spectator or London or the Foreign Office or Britain (next stop: the world?), having meetings and work lunches, getting on with stuff. And he can grope women at the same time! And for much of that time, it was a “different time”, so at worst he’d probably get an awkward brush-off; at best, he’s advertising his lascivious intent widely while also getting on with work. It’s very effective and time-efficient, like a leafleting campaign for an affair.

Perhaps, back in the “different time”, it seemed like all the chaps were at it. Apart from absolute snowflakes who probably request permission in writing from their penises before masturbating, am I right, guys? Guffaws. Ring ring: take a call, squeeze a bum, swig a claret, issue a veiled threat, ruffle hair, shy grin and press conference!

This is not to say there aren’t people claiming to believe Johnson’s denial. Tory MP Gillian Keegan bravely held the line on Channel 4 News with: “I’ve no reason not to believe him.” That feels like an attempt at psychological self-defence: “There’s no reason for me even to consider whether I believe him because, if I think about whether I believe him about this, I might think about whether I believe other things he says and that might be unsettling.” Unfortunately there are three big reasons for not believing him: 1) his history of lying, 2) his history of fornicating and 3) the fact that the only other account of the events in question completely contradicts his own.

Twenty years ago reporting a grope was as unlikely as a medieval peasant going to the king to complain that his local baron was homophobic

Other apparent Johnson believers include the chancellor of the exchequer, Sajid Javid, who said he “totally trusts” Johnson over the allegations, the Conservative chairman, James Cleverly, who said: “If No 10 say it didn’t happen, I believe that”, and the Tory chief whip, Mark Spencer, who announced that “if the prime minister says it didn’t happen, it didn’t happen”, a shaky rule of thumb for analysing British politics at the best of times, but currently it reads like a joke. Speaking of which, Liz Truss, the international trade secretary, said Johnson was “absolutely a feminist”. Though perhaps she thinks feminist means someone who fancies women.

In a sly dig at Charlotte Edwardes, Spencer added: “If I were a victim of some sort of assault, I would go to the police straight away.” That’s quite a shitty remark – it’s clearly not for want of viciousness that Spencer is the first government chief whip in living memory unable to win a single vote in the House of Commons, so we’re forced to consider incompetence. But is he really saying he’d expect young women whose bosses groped them at boozy lunches in the 90s to go to the police? Is that how much groping he thinks went on back then – the amount the authorities were told about? Most of it goes unreported now, but 20 years ago reporting a grope was as unlikely as a medieval peasant going to the king to complain that his local baron was homophobic.

But the efforts of those keen to boast complete credulity of their master’s unlikely claims were undermined by more equivocal support in other pro-government quarters. The health secretary, Matt Hancock, said: “I entirely trust what [Charlotte Edwardes] has to say”; Dominic Cummings’s wife, Mary Wakefield, while denying that she was the other woman referred to in the groping allegation or that she knew anything about it, nevertheless said she liked and admired Charlotte Edwardes, an interesting thing to make a point of saying of a woman who, according to the prime minister, has just maliciously libelled him; and, perhaps least helpful of all the help Johnson received, Toby Young chipped in with: “Back then at the Spectator… people complained if Boris didn’t put his hand on their knee.”

I reckon those people all think the groping happened. Which makes me wonder whether anyone at all, in their heart, genuinely believes Johnson’s denial. A few weird contrarian conspiracy theorists who think the Earth is flat? Or just no one at all? I think it really might be absolutely nobody. The prime minister, renowned for his dishonesty, may finally have made a statement disbelieved by all.

So what’s the division? It’s over whether it matters. Nearly everyone thinks he did it, but some people don’t mind. Politicians can’t quite get away with admitting they don’t mind, so they express that feeling by saying they don’t believe it happened. It’s what fascists are doing when they deny the Holocaust.

Most Johnson loyalists believe the grope happened, they just don’t much care. Or, I suppose in some cases, don’t care at all. Or, inevitably in a few cases, actively like it and think it shows the sort of ruthless libido Britain needs if it’s going to really screw the EU. So watch out, Barnier – we’re sending in Johnson, the handsy liar.