MPs have demanded urgent action must be taken to end the "widespread" sexual harassment of girls.
It's after a shocking picture of the scale of abuse in schools was laid bare. Groping, name calling and bullying is part of "everyday life" for schoolgirls.
But it's dismissed by teachers as "just banter", a Commons committee found.
Its disturbing report warned that some pupils, including those in primary school, were being exposed to hardcore pornography. These images are twisting their views on sex and relationships.
MPs pointed to research that found nearly a third of 16 to 18-year-old girls said they had experienced unwanted sexual touching at school. Most girls and young women had faced some form of sexual harassment at school or college.
Pupils also reported hearing girls being called a slut or a slag on a regular basis, according to research highlighted by the Women and Equalities Committee.
It heard the "slapping of bums and flicking [lifting up] of skirts" was common while one teacher told how they had had "many young girls sobbing and humiliated in my office because partially naked images have gone viral".
Too many schools were failing to deal with the problem while the Government and watchdog Ofsted had no coherent plan for how the causes and consequences should be tackled, it found.
Conservative MP Maria Miller, who chairs the committee, said: "Our inquiry has revealed a concerning picture. We have heard girls talk about sexual bullying and abuse as an expected part of their everyday life; with teachers accepting sexual harassment as 'just banter'; and parents struggling to know how they can best support their children.
"It is difficult to explain why any school would allow girls to be subjected to sexual harassment and violent behaviour that has been outlawed in the adult workplace. The evidence shows it is undermining the confidence of young women. Failing to reinforce what is acceptable behaviour could well be fuelling the 'lad culture' that the Government has already identified as a problem in colleges and universities.
"Despite this, the Department for Education and Ofsted have no coherent plan to ensure schools tackle the causes and consequences of sexual harassment and sexual violence."
Girlguiding's Girls' Attitudes surveys found that in 2014 59% of girls and young women aged 13 to 21 said they had faced some form of sexual harassment at school or college in the past year.
MPs also highlighted polling by campaign group End Violence Against Women in 2010 that reported 71% of all 16 to 18-year-old pupils had heard sexual name-calling, such as "slut" or "slag" used towards girls at schools regularly. 29% of girls in the age group told of being groped.
The report said there was not enough information to show sexual harassment and violence was a growing problem in schools but there was "significant" evidence to suggest that easier access to pornography was exacerbating the problem.
It warned that the type of pornography many children were exposed to was often "more extreme" than adults realised and it was having a "negative impact" on youngsters.
Girlguiding's advocate panel, a group of 14 to 25-year-olds who represent the movement's young members, said: "As young women, many of us are still in school and experience or witness sexual harassment from groping to cat calling on a daily basis.
"It's humiliating and frightening and affects what we wear, where we go, our body image and our confidence to speak out in class. Yet, it's often dismissed as banter or a compliment and we are told we are overreacting or being over sensitive.
"It needs to stop. Schools should be safe and empowering places and we should feel able to learn without fear. That's why we need a zero tolerance approach to sexual harassment where schools take the issue seriously, sex and relationship education is compulsory, and schools are held accountable for preventing and tackling sexual harassment."
MPs called for all schools to collect data on reports of sexual harassment and police should keep specific records of incidents.