This isn’t the kind of public display we’ve seen when an MP or celebrity. Picture: YouTube.com

London - Who didn’t smile at the snap of Mike Tindall with his hand cheekily on his wife’s royal posterior, while she, in turn, reached towards his muscular bottom?

They didn’t care who saw this sweet, funny display on Sunday. What better sign could you have of a merry marriage: a couple so happy in their own skins and with each other they prove it with an instinctive, loving pat?

Yes, the gesture might imply they fancy each other, too - but, believe me, that’s not what matters. What’s important is what lasts in the best relationships: affection and intimacy.

This isn’t the kind of public display we’ve seen when an MP or celebrity, who’s done something he shouldn’t, makes sure he is "snapped" with his arm placed strategically around his poor wife’s shoulders. 

Or when a rich guy’s arm draped over the young trophy blonde boasts: "Mine." We can all see through the cynicism.

Zara, 37, and Mike, 39, are the last people to bother about making an impression. Why would they? They might be a part of the extended Royal Family, but the equestrian and the former rugby player are as unstuffy as they come.

When they’re snapped, showing their affection in public, which is impossible to avoid nowadays, those moments are still utterly private. It’s all about them and what they feel about each other - so who cares who sees?

They’ve been married for seven years, have two little girls, the youngest of whom was born seven weeks ago, and the affection between them is palpable. A casually placed hand on a knee there, a loving kiss on the cheek there, it comes so naturally to them.

Thirteen years of writing an advice column has given me (sadly) more glimpses into unhappy relationships than I ever dreamed possible.

Asked about common themes in failing relationships, I sometimes generalise that men’s problems often centre on the lack of sex, whereas women yearn for emotional intimacy.

So many women - and some men, to be fair - desperately crave a loving hand held out and a gentle voice saying: "Are you all right, love?" How I wish the husbands who resent their wives’ "coldness" would realise that if experience tells a woman that he’s holding out his arms only because he thinks it will lead to sex, then she might well avoid that cuddle.

To me, one of the most beautiful sights in the world is a very elderly couple walking slowly along the street, hand in hand.