Why sex isn't key to a happy marriage

As Sir Michael Holroyd - husband of novelist Dame Margaret Drabble - admits to having 'romantic relationship without sex' with a theatre critic, Rowan Pelling says there is something beautiful about a marriage that moves beyond jealousy

A year or so ago, I was wandering round the V&A when I found a little side gallery I'd never visited before.

There were delicate architectural drawings on display of colonial buildings from the Arts and Crafts era. When I leaned in to look at the notice beside a design "for a house in Tsinan" by Oliver Hill (begun in 1922), the text was so unexpected and quietly subversive I had to photograph it with my iPhone.