Natalie Collins, a Christian from The Day Programme, which teaches about abuse and exploitation in schools, told Premier's News Hour: "It's a really sad state of affairs that we don't believe there is better behaviour available for boys and men in society - so I think there's this sense that 'boys will be boys'."
- 200 rape allegations in 2015 in schools
- FOI search showed in three years 5,500 sexual offences recorded in UK schools
- YouGov poll of 16-18 year olds in 2010 found 29% of girls had experienced unwanted sexual touching at school and 71% said they frequently heard sexual name-calling towards girls at school
She was speaking after figures reveal there were 200 allegations of rape recorded in British schools last year.
It's been announced a group of MPs will examine the scale of sexual violence and intimidation in schools in the first investigation of its kind.
She said: "There's this expectation that boys will behave in sexually inappropriate ways."
The Women and Equalities Select Committee says that research suggests some teachers turn a blind eye to sexual harassment because they think pupils are just experimenting.
In addition to this, the youth charity Fixers found that some schools are not playing their part in recognising the pressures young people face when dealing with matters of sexual harassment and sexual bullying.
Natalie Collins told Premier there is unfair judgement in schools: "The boy will often be congratulated and the girl will be judged.
"So often the social cost of talking about this stuff is enormous for girls and if schools are treating them as both as bad as each other, without understanding the coercion, the manipulation [and] the power imbalance between this boy and this girl, then what we're likely to see is it not being taken seriously."
She added that schools need to better-teach about healthy relationships.
She said: "We're not providing education that counters the message in pornography - so young people, both boys and girls are seeing that this is the normal way to interact sexually, to interact with the opposite sex in ways that are humiliating, degrading and violating, from males to females."
The Committee's probe into sexual violence in schools runs until May 22nd and will investigate the scope of the problem, whether levels are increasing, the impact of online sexual bullying, to what extent teachers are the target for harassment, and what can be done to combat the situation.
Listen to Premier's Antony Bushfield speak to Natalie Collins here:
