A few weeks back I wrote a column questioning why we put monogamy at the moral heart of heterosexual relationships.

I’d been pondering the question after watching a decent and intelligent politician, John Della Bosca, being forced to resign because he’d been having an affair.

It seemed to me that this was a matter between him and his wife and had nothing to do with his ability to execute his public responsibilities.

I suspect many people thought the same. But the political heat proved too much.

I wrote my column partly to see how readers would justify monogamy. I knew in advance that it’s one of those ‘family values’ you’re not supposed to question.

Despite the fact lots of decent married people are having affairs, the subject is generally off-limits at dinner parties.

The general response to even academic discussions of why we accept that sexual fidelity is the best foundation for a long term relationship is: “People tried that in the 60s and it didn’t work”.

The allegedly tragic case of Simone de Beauvoir and Jean-Paul Sartre is often raised in the same breath. (Though if you read Simone’s writings you discover she often felt happy and liberated by their open relationship, as much as she occasionally felt miserable.)

Polygamous Wives takes on this vexed topic and does so with real finesse and nuance. The documentary makers have resisted any temptation to lace the voice-overs with judgmental commentary. Their selection of the two families allows many things to be said through the voices of the subjects.

The program follows the lives of two very different families. One is headed - and that’s the only word for his role - by an ex-Rabbi who has seven defacto wives. Phillip, a horsetrainer who lives in Sussex, believes that God spoke to him and told him to become polygamous.

The other family is made up of Kestrel, a man without a patriarchal bone in his body, and his two partners Summer and Lucy. Summer and Kestrel were in a long term monogamous relationship when they decided to invite Lucy to join their house in a domestic and sexual sense.

They all have sex with each other and practice Tantric mediation. It will not surprise well-travelled readers to learn that they live in California in a logwood cabin.

The contrast between the way these two families approach polygamy couldn’t be sharper.

For Kestral, Summer and Lucy the focus is very much on empathising with each other’s needs and desires in a very democratic and open way. Summer is an attorney and a highly intelligent woman who has clearly thought through the pros and cons of
her choices.

Kestrel is equally articulate about the benefits and costs of living in a triangle. He observes sardonically that many men would think it’s an erotic dream come true to be able to have sex with two women who are also into each other.

But he then observes that: “Having two women scrutinize your male behaviour... if you’re angry or controlling that they’re going to generally look at you together... the erotic dream will last one night... I don’t know that everyone wants to be that open”.

Back in Sussex, Phillip exhibits none of the self-reflection that so clearly characterises Kestrel’s relationship to his two lovers. While denying that he’s in anyway controlling of the women he was allegedly commanded by God to marry, Phillip talks about them in ways that certainly made this feminist deeply uncomfortable.

In one revealing interview he compares his ability to train horses to his ability to train women: “With a wife the same thing applies but instead of an understanding of the body language... a human being is much more complex. The way I would train a wife is by discerning the motive of her heart."

Oh really? Is that a whip in your pocket or are you just pleased to see Wife Number 5?

Whatever you think about the possibilities of long term love surviving without the moral constraints of monogamy, this documentary elucidates one thing: all serious relationships involve rules and the negotiation of those rules. There’s no free lunch when it comes to love and long term sex.

In the case of Phillip and his seven wives, he seems to be the one laying down the law and handing out the discipline. In the case of Kestrel, Summer and Lucy the hierarchy is much flatter. There’s something very charming about their genuine desire to love each other well and make each other happy.

Good for them I thought. And let’s leave them alone to do it well.

I’d much prefer to listen to them talk about their attempts to find a different way of relating than watch a documentary about miserable people in a monogamous relationship who stay glued together for fear of losing property and status.