Future historians will face a tricky challenge when they come to study the sexual attitudes of early 21st-century men and women. They will open a newspaper of the time, or read an ancient blog, and will discover that in 2012 some women showed their bare breasts in mass-circulation tabloids, while the breasts of others were secretly photographed and then sold for profit. One was accepted as a jolly British tradition, while the other was seen as a terrible scandal.

Turning the page, the historian will become even more confused. The same princess whose breasts should not have been photographed is shown descending steps from an aircraft, a gust of wind blowing up her skirt, revealing her legs. The newspapers which disapproved of topless pictures in tabloids carry photographs, with sniggering captions, of bare-breasted Solomon Islanders meeting the princess.

We have become lightly pornified over the past few years. Like the Victorians, we have learned to disguise our sexual curiosity in the cloak of morality, scolding others for what we secretly find exciting. The daily appearance of Sun Stunnas and Starbirds over the past 40 years can only have contributed to the new prurience and, quite clearly, Lucy-Anne Holmes’s calm, reasoned “ No More Page 3” campaign deserves supporting. Those ridiculous photographs belong to another age and should be an embarrassment to those who publish them.

Like the Victorians, we have learned to disguise our sexual curiosity in the cloak of morality

It is odd, though, that a wider problem, the hypocrisy which surrounds the way women are viewed in the media generally, tends to be taken for granted. For the reader of an apparently respectable newspaper, a photograph of a young princess’s skirt being lifted by the wind – or an actress showing more than she intended at a film premiere – are after all serving the same function as a Page 3 model in The Sun.

A tabloid editor will argue that he is only publishing pictures of attractive young women, and the same argument has been deployed by the magazine editors putting out the topless photographs of the Duchess of Cambridge. Here is a beautiful couple, they say. They are married and in love. And – this part is left unsaid – we’d really like to see what they get up to.

It is bogus to pretend that there is no connection between this grubbiness and the leering, seen as entirely acceptable, which accompanied last year’s royal wedding. It may be marginally less intrusive to photograph Pippa Middleton’s bottom than her sister without a bikini top, but the impulse behind it, and the pathetic, randy press commentary, is the same. Hooked on low-level voyeurism, which is every bit as demeaning as leering at topless models, society becomes a dirty old man, trying to catch a flash of nipple or knickers. Then, to make us all feel better, we trill with disapproval.