"We are the generation of self-help books," he says. "We have all these books that are trying to show us how to extricate ourselves from painful relationships, but in fact we should be taking pre-emptive action. There is an ancient Jewish aphorism which declares that the difference between the wise and the clever man is that the clever man can extricate himself from a situation into which the wise man would have never got himself in the first place." He believes that problems in relationships occur because couples cannot find a way to maintain both passion and intimacy. "We need passion, we need to tear each other's clothes off, but we also need to be close as friends. What we want is contradictory," he says.
As a rabbi and counsellor for the past ten years, married at 21 and now with six children, he feels well-qualified to advise on resolving this contradiction. "Judaism is a sexy religion," he says. "It celebrates sexuality. For a priest not to marry is normal, for a rabbi not to marry is a sin."
And he is not afraid to put forward unfashionable theories. For example, while most sex experts believe trust is the most important component of any relationship, Rabbi Boteach believes that a spice of jealousy is a healthy thing. "Men have a very short sexual interest span - that's why they want lingerie," he says. "A smart woman will not fault her man for being like a walking radar tower, looking at every passing pair of legs. She will make sure that she is the woman he seduces, rather than his secretary."
He is very much against masturbation. "My views are another heresy! The sex gurus say that masturbation is good, but in fact it's bad: it gives an outlet for sexual need. Couples should need each other; if they masturbate they are not as hungry, not as dependent. If the captain of a steamship pulls on his horn and lets the steam escape, it leaves his tugboat dead in the water," he adds, alarmingly.
Rabbi Boteach also believes that immodest dressers bore their partners. "People say that to dress modestly is conservative, religious crap, but when you see a woman who is well-dressed, you undress her with your mind.
Men and women, he says, can't be lovers and best friends simultaneously; the Jewish teaching that forbids sex for 12 days of the month allows partners to spend two weeks as lovers and then two weeks as friends. Two weeks' abstinence, he explains, allows time to "build up sexual energy. And when sex is truly intense, it brings a tidal wave of positive emotion, it leaves two people feeling really good about each other."
Rabbi Boteach was born in Los Angeles in 1966, and raised in Miami after his parents split up when he was eight. It was the memory of this divorce that led him to value wedlock very highly indeed. "I idolise marriage, I am obsessed with marriage, because I believe divorce destroys children. It certainly scarred me for life, and I wanted to be a better husband and father to my own wife and children." He practises what he preaches, and married straight after completing his rabbinical training ("I found a woman who could put up with me, a blessing from God"); their sixth child was born a couple of months ago. "Loneliness," he says, "is the world's greatest curse, and happiness with an equal of the opposite sex is its greatest blessing."
'Kosher Sex' by Shmuel Boteach is published by Duckworth on 21 May at pounds 9.95Reuse content