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.