This article claims that experts told UK MP's that sexual harassment is increasing in schools because of internet pornography. However, I haven't seen any references to studies done on the subject so I'd like to see where the facts stand.
Note that while this question is aimed at the UK, an answer could reasonably be supported by evidence from other countries.
The article says:
Experts told the Women and Equalities Committee that online pornography had led to increased acceptance of sexual violence and harassment towards women. A "normalised culture of sexual harassment" in England's schools meant girls were changing their behaviours, rather than boys being challenged. And change would come only with a shift in attitude among the wider population.