"I think I'm obsessed with marriage," he says, his vowels as American as when he arrived in the UK a decade ago, aged 21. "It's just that I've discovered in counselling hundreds of couples - and I will debate anyone on this subject - that a healthy sex life is the essence of marriage, certainly in the early years. Sex takes the edge off life. And if you feel intimate with the person you are married to, then suddenly whether dinner is ready on time or if the house is tidy for the husband, these things aren't important."
I don't want to wreck his flow and so only make a mental note of this strange idea of creating a tidy house for the husband. But he's still concentrating on that three-letter word.
"I think the modern world has destroyed sex. For men the great issue - and many men tell me this - and the reason they don't enjoy sex is that they know they are always being rated. All the Viagra in the world isn't going to cure impotence because the cause isn't clinical, it's fear of performance. For women it must be the same. They feel evaluated constantly. A recent study in the United States shows women faking it 64 per cent of the time. Once sex becomes a performance, once it becomes about anxiety..."
I interrupt. "So when did you become so interested in this subject? Perhaps because I've avoided the S-word, the rabbi brandishes it.
"I wouldn't say that I am interested in sex in particular, but there is a consistent theme in my books that attraction has to be preserved in marriage. I don't mean physical attraction. I mean holistic attraction to the entire personality. People think relationships are about compatibility and ask me `why aren't you writing more about communication'? But I don't agree that it is about communication. A man is not drawn to a woman because he might have a great conversation with her. He is just drawn to her. If relationships were all about compatibility, we would all be gay."
Perhaps, with that, it is time for a pause before we move on to Monica Lewinsky, loneliness, ostracism and a commandment or two.
We are sitting in the Wigmore Street offices of L'Chaim, founded by the rabbi in Oxford. The group, which plans to bring - as he puts it - Judaism to young Jews, has been a phenomenal success. Guest speakers have included Mikhail Gorbachev, Boy George and Diego Maradona. Perhaps if he'd stopped there, the rabbi would be feted as a maverick. But he didn't.
His triumph - and undoing - is that he is a populist and a bit of a publicity junkie. He is addicted to sound bites. Here, for example, are just a few from our conversation:
"There are different kinds of Hasidic. I'm more the Giorgio Armani kind," he says.
"Cigar? I smoke Monte Christo Number Twos but, after the [Monica] Lewinsky report, you are afraid to put a cigar in your mouth.
"The main problem here is that British Jews feel like guests in their own country. In general Jews are trying to be more British than the British, and religion here is more about - let me make sure I use the right words - respectability than effectiveness.
"I am absolutely amazed that anyone was prepared to marry me. When you have an inflated ego and you are totally self-absorbed and a woman is still interested in you, then that's impressive. I thought, she must be a good girl."
But his goal is not to be a media darling - or, as he calls it, a "court Jew" - for the Today programme or anywhere else for that matter. Instead, he aims to write the ultimate religious self-help book. "Isn't it incredible that religion missed the boat with the whole self-help thing?" He is not only on the boat, but steering it, thus Kosher Sex and Dating Secrets of the Ten Commandments.
His parents' nasty divorce made for a traumatic childhood which, he says, made him needy, self-obsessed and ambitious. On the plus side, it also helps him relate to most people and fed his obsession with marriage. It also gave him training for being the outcast that he now is. This year he is up for the Preacher of the Year award, and it was a bit of a stretch to find a synagogue that would have him, even for a day.
Appropriately, he spoke on the three levels of loneliness. "I've turned to God personally, in prayer, over the past few months. My wife is amazing,'' he said. "She's done her best to heal me. When you are isolated by your community, especially when it's written on the front page of the Jewish press all over the world and you cannot find a place to give one flippin' sermon ... I think there is a great consolation in prayer. I always tell the students that prayer is not a religious ritual, it is a psychological need. It's the ability for men just to talk to a being that can understand his pain. But we are a very lonely generation."
I am intrigued by his ideas on dating, mainly because the only dates that I'm aware of are pieces of fruit. He assures me otherwise. His thinking on the Ten Commandments and dating is best described as lateral.
In the book, which will appear in the spring, there will be about 40 secrets for every commandment. So here's a sample. Evidently the one that tells us not to swear is that we shouldn't state the obvious: "You need to develop your personality, not just your body." Thou shalt not steal is all about not lying to each other and stealing their hearts. The one that says: "I am the Lord Your God" is all about making your date the centre of your universe for the evening. And, for men, it serves as a reminder that they are not God.
All of this is fuel for his populist cause but, predictably, we are soon back on more familiar ground. "The fact is that the rabbi who talks about sex is popular because it is a confounding subject. Judaism has so much to say on the subject. It has volumes - libraries - of advice about this. Why haven't rabbis taught it? The answer is that they've adopted a very Christian view that sex is dirty. Absolutely. Yes, I think that many Jewish clerics today are influenced by Christian thought without even being aware of it." But not, obviously, this Jewish Orthodox pariah.Reuse content