Allison Pearson points out that porn is having some bad effects on girls.

A GP, let’s call her Sue, said: “I’m afraid things are much worse than people suspect.” In recent years, Sue had treated growing numbers of teenage girls with internal injuries caused by frequent anal sex; not, as Sue found out, because she wanted to, or because she enjoyed it – on the contrary – but because a boy expected her to.

A couple of the women present said that they had forced themselves to have toe-curlingly embarrassing conversations with their teenagers on the subject. “I want my son to know that, despite what he might see on his laptop, there are things you don’t expect a girl to do on a first date, or a fifth date, or probably never,” said Jo.

I was having dinner with a group of women when the conversation moved onto how we could raise happy, well-balanced sons and daughters who are capable of forming meaningful relationships in an age when internet pornography is as freely available as a glass of water. Porn has changed the landscape of adolescence beyond all recognition. Like other parents of our generation, we were on a journey without maps or lights, although the instinct to protect our children from the darkness was overwhelming.

And what boy expects boy gets.

There was stunned silence among the mothers around that dinner table, although I think some of us may have let out involuntary cries of dismay and disbelief. For Sue’s surgery isn’t in some inner-city borough where kids may have been brutalised or come from cultures where such practices are commonly used as contraception. Sue works in the leafy heart of Hampshire. The girls presenting with incontinence were often under the age of consent and from loving, stable homes. Just the sort of kids who, only two generations ago, would have been enjoying riding and ballet lessons, and still looking forward to their first kiss, not being coerced into violent sex by some kid who picked up his ideas about physical intimacy from a dogging video on his mobile.

Oh that’s nothing – the other day Teen Vogue (which is aimed at teenage girls) had a piece on how to submit to anal sex.

The harm, of course, is not just physical. A study this week revealed that the number of schoolgirls at risk of emotional problems has risen sharply. Scientists for the Journal of Adolescent Health were surprised to see a 7 per cent spike in only five years among girls aged 11 to 13 reporting emotional issues. Boys remained fairly stable while girls faced “unique pressures”. Researchers said the causes could include the drive to achieve an unrealistic body shape, perpetuated by social media and an increasing sexualisation of young women.

But there’s always Ivanka to look up to and Gwyneth to sell us jade eggs.