Why are so many young women buying into polyamory?

The saddest thing I saw this week was a dating advert written by a woman – let’s call her Jane – looking for a man to start a family with.

There was nothing sad about Jane per se: she’s attractive and accomplished in the usual alarming millennial way. Not only does she have a well-paid job in a tech firm, but she climbs, plays the cello, writes plays and is a near-professional baker. Because young people these days don’t drink until they pass out, they have time for hobbies.

Jane is also polyamorous, she mentioned in the ad, just in passing. She is in a committed romantic relationship with three other people and they live in a shared house – and this, I’ve discovered, is par for the course now in parts of London and across the US. Some 5 per cent of Americans say they’re ‘polyamorous’, and given that almost everyone over 50 is monogamous, this means an awful lot of poly youth.