He looked slowly around the living room of my freshly painted flat and then gestured in exaggerated fashion to the books and ceramics crammed on shelves, to the canvases on the walls and my kids’ instruments strewn on the floor. “Well, your life looks OK to me,” he said.

“Lots of Jews had nice apartments in 1930s Berlin,” I retorted. “The pessimists among them went to Hollywood. Need I spell out what happened to the optimists.”

It was an easy, if apposite, riposte. But I was done with patient argument and trying to appear less emotional than I felt: done with trying, I am almost ashamed to say, not to appear the hyperbolic Jew of anti-Semitic ridicule. It was 2am and I had been arguing about Corbyn and the problem of left-wing anti-Semitism for almost three hours. I was nearing breaking point.

My adversary was Sean*, the guy I’d been seeing since January – by now, it was September – and who I really liked. So when he’d asked earlier in the evening if we should meet next Saturday and I said no, that I had a dinner date with a cousin who was over from Israel, and Sean replied, laughing, “Ooh, do you think she’ll be scared to set foot on our Jewish unfriendly soil?”, I asked him calmly what he meant. And when he replied, still chuckling, that Labour’s anti-Semitism had been massively overstated, that it was essentially a tawdry attempt to smear Corbyn, I took a deep breath and answered him properly.

I explained to my lover that this is no laughing matter, that there is consensus across Anglo-Jewry that there is a serious problem of anti-Semitism in Labour, and this means he should take it seriously too.

I said that if Tory politicians had done half the things to any other ethnic group that Corbyn has done to the Jews, leftists would be baying for blood.

And when he asked, as Corbynistas always do, what exactly Jeremy has done, I went through the grim list: his claim that Hamas and Hezbollah are dedicated to peace and justice, even though Hamas’s charter calls for the destruction of the Jews; his defence of the blood libeller Raed Salah and the conspiracist Rev Stephen Sizer, who blamed Israel for 9/11; his membership of Facebook groups where deeply anti-Semitic posts are the norm; and his siding with those behind the now infamous Nazi-style mural showing hook-nosed anti-Semitic caricatures, getting rich on the backs of the world’s poor.

And then I tried to explain to the man with whom I’d just shared my bed just how painful this all was. I told him I had been a member of the Labour Party since the age of 16, and that like many left-wing British Jews I now felt politically homeless. I told him that when my Warsaw-born mother came to Britain in the Sixties she stopped feeling scared of being Jewish but now, 50 years later, she was feeling frightened again. I told him that in the last decade 40,000 Jews have left France, a country where Jews make up less than 1 per cent of the population, but where one in two racist crimes are against them; and that this should be a warning to the British left of what happens when you are apathetic to anti-Semitism, as the French left certainly has been. And I told him that mocking Jews when they call out anti-Semitism, is analogous to white people telling black people they are imagining their experiences of racism.

“Well, it’s not quite the same,” he said.

“Why?” I replied, though I knew what was coming.

“Well,” he continued slowly, “Jews have money, don’t they?”

“Do we?” I replied.

“OK, maybe not you,” he conceded, “but you’re not poor, either.”

I’m not, no. When Sean said “your life looks OK”, he was right. But I know plenty of Jews who do struggle financially. At my children’s Jewish primary school, for example, 12 per cent of pupils were eligible for free school meals, compared to the national average of 14 per cent. And, yes, I also know plenty Jews who are well off.

But the point is that anti-Semitism is never about Jews and the actual lives they lead, and one of the central tropes of anti-Semitism is the pernicious association between Jews and money. It never, ever goes away. For many on the left this means that the Jews can never be oppressed or exploited but are, in fact, the source of others’ oppression and exploitation. That’s why Corbyn couldn’t see anything wrong with that vile mural. It matched his world view.

And if you think that Jews are never oppressed or exploited, if you don’t want to study history, Jeremy, and so don’t know that no group prejudice has displayed such intensity and historic continuity in different times and places as anti-Semitism – that Jews are the most persecuted group in modern times – then it also stands to reason that you won’t accept Jews need protection from hatred.

The International Holocaust Remembrance Alliance (IHRA) working definition of anti-Semitism was written in response to this hatred, a definition to help European police forces and prosecutors better understand it. That’s why the Labour Party’s refusal to adopt it in full for so long caused huge hurt and pain.

So when we got on to the IHRA and Sean questioned its very raison d’etre – “Britain has hate speech and anti-discrimination laws. Why do Jews need additional protection?” – I gave up. We had been rowing about the problem of anti-Semitism for more than three hours and I had clearly got nowhere.

“I think it’s time for you to leave,” I said.

Corbynistas’ standard response to Jews is that they know their claims of anti-Semitism are false and that they make them to smear the Labour leader. This doesn’t explain why this woman threw her (now ex) lover out of her freshly painted flat at 2.30 am.

*Name has been changed.