How we manage love and relationships in a way that works for the 21st century is the subject of the moment. A book on the theme, The New Rules of Marriage by Catherine Hakim, is published at the end of this month. Hakim caused controversy with her last book Honey Power, in which she talked of women's "erotic capital" as something they should use to further themselves. Her latest promises to have as much impact.

In The New Rules, Hakim opines that we in Britain have a very high rate of marriage breakdown because we have such an old-fashioned and puritanical approach to infidelity, whereas in Mediterranean countries such as France and Italy they deal much better with it. In our straitlaced, Anglo-Saxon culture, she argues, when we do have affairs we manage them badly and if they are discovered divorce is often a knee-jerk reaction. It is time, she suggests, for us to get real.

This is particularly so as the internet offers opportunities unheard of before, which tempt more and more people into unfaithfulness. Yet if these affairs and others that might amount to "recreational sex" can be treated as "playfairs" as in France and elsewhere, they need not harm the marriage – so often the fallout – which is the solid root to life with home and children.

So Hakim explores in her book how "playfairs" do and don't work, but from the perspective of the best way of dealing with something that will not go away.

Another book, just out, is Rewriting the Rules by Meg Barker, senior lecturer in psychology at the Open University and also a sex and relationship therapist. She too sees relationships as trapped in conventions, "the ties that bind", which need re-examining for the new millennium.

Her thinking is that so many people are struggling with relationships these days that we need to question assumptions about relationships and allow for changing mores, predilections and what makes us happy.

Meanwhile, acknowledgement that relationships are not what they should be is seen in the £500,000 given to researchers at the Open University to conduct the large-scale The Enduring Love? research project. This will study the breadth and diversity of relationships in the 21st century and the factors that enable couples to sustain long-term relationships. They will use the information to guide government as to how it might better support relationships and family life.

I became interested in the idea of how home life can be strengthened by re-thinking how we deal with sexuality and intimacy, when writing my book A Home for the Heart. In the chapter Not Forsaking All Others I suggest family life might be improved if we were less judgemental of the unorthodox. For instance, one polyamory family, with a child, I interviewed are convinced their structure is what cements the home.

Shouldn't we listen to these advocates for changing attitudes at a time when more than 40% of marriages end, on average after eleven years, and increasing longevity undoubtedly challenges the notion of lifelong monogamy. There will not be a panacea for everyone, but if more people could be happier more of the time in their relationships, wouldn't we all benefit?