I’ve just been reading some books on infidelity including Mating In Captivity by Esther Perel and How Can I Ever Trust You Again? by Andrew G Marshall. Perel takes the view that monogamy is an outdated concept and that while affairs are rightly the end of some relationships they may even improve others.

A question that’s often asked about all this is: Are humans naturally monogamous? A lot of people seem to think this crucial. But it’s completely the wrong question. The human species, as I’m often pointing out, is the only species that can be unnatural. Being unnatural is what separates us from all other animals.

It may be natural to eat meat but we can decide not to. It may be natural to let hair grow where and how it will but nobody does. It is unnatural to fly but millions of us do. Asking what’s natural is totally irrelevant. The right question is: Which is more conducive to happiness in a relationship, monogamy or unfaithfulness?

The answer won’t be the same for everybody but I think that for the majority of people the answer is pretty clear.

An often quoted statistic cited to prove that humans aren’t monogamous in practice is this: Over the lifetime of a relationship between 30 and 40 per cent of people will be unfaithful at some point. But that certainly doesn’t prove it to me. Let’s take a married couple together for forty years who had sex an average of twice a week. That’s 4,160 bonks. Now let’s suppose the man had a one year affair also averaging sex twice a week. That’s 104 bonks. That means 98 per cent of the man’s bonk were with his wife while, for her, all of her sex was with her husband. That doesn’t sound to me like the death of monogamy.

A long time ago when I was recently divorced I was also meeting a lot of recently divorced women and something struck me very forcibly. It was taking two years for those women to get over the whole thing just on a superficial level. Deep down I’m sure it was taking longer. How much pain was due to the husband’s unfaithfulness and how much to the divorce I can’t say, nor can I say how those women would have felt if the marriage had survived. But what I saw made me introduce my own rule: Never mess around in someone else’s life. In other words, if you’ve promised to be faithful to another person you’d better think very carefully before breaking that promise. And there’s also the ‘other woman’ and the ‘other man’ to consider – if that other person is looking for a serious relationship and you’re not then you have no right to wreck that other person’s happiness by pretending.

Marriage counsellor Andrew G Marshall disagrees with Perel on many counts but accepts that affairs can have a happy outcome.’ The most miserable couples I ever see are the couples who are trying to recover from an affair,’ he says. ‘But equally, the happiest couples I end up with are the couples who have recovered from an affair. Affairs make you scrutinise every element of your relationship, more so than any other issue. And so if you do survive them, you will be stronger and happier as a result than you ever were before.’

What’s significant here is the assumption that you can only ‘scrutinise’ your relationship when one of you has had an affair. The fact is, time, energy and money that’s expended on an affair is time, energy and money that’s not going into the regular relationship. I’d suggest seeing what happens when you do focus on your long-term relationship. The result might be incredible.