It was 50 years ago this summer that we first had sex together – in a tent in Cornwall – and it is still something we enjoy. Monogamy suits us. Apart from one short and ill-advised venture off-piste, caused by midlife angst, we have remained faithful. We don’t make love so often these days – three to four times a month compared with three to four times a week in our heyday – but our sex life has matured as we have. As students, we could, and did, do it in the back of a Mini; the physical side of sex is now less carefree. Sexual activity at our age – we’re in our late 60s – can sometimes seem like a Pilates class, and we are having to consider imaginative alternatives.

The missionary position has a lot to commend it; we like to look at each other – partly to check in and make sure the other is OK, but mainly because it is a relationship activity. Occasionally we have seen the absurd side and collapsed into giggles about what a Martian would think if it caught us in this ridiculous pose.

Apart from making babies and having fun, we have also needed sex from time to time – as a comfort in times of stress, as a way of making up after sulks (we were very good at those) and as a release at times of celebration. There have also been difficult moments along the way, such as having a house full of babies or teenagers, which is not the most congenial environment, although somehow we managed. Our relationship could not have survived without sex, nor would our sex life have survived without our relationship. We know we are extremely fortunate.

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