They have "unrealistic expectations" in the trouser department - and about their partners' stamina.
It means unsuspecting chaps risk being rated flops in bed, a study by psychologists found.
The revelation - amid a boom in women viewing internet porn - led to scientists behind the research warning yesterday: "Genitalia can be digitally or cosmetically altered, depicting larger than average penis size."
Sex expert Kaitlyn Goldsmith, who led the study in Canada, said of romps in X-rated films: "Intercourse is shown to last longer than average, men sustain erections longer and women experience orgasms more easily than in real-world encounters."
The research at the University of New Brunswick involved 1,000 adults, two thirds of them young women.
It found porn viewed by females was "linked to consumers' dissatisfaction with their partners' appearance".
Women ran the risk of "unrealistic expectations for sexual performance".
The shock for fellas comes after Pornhub, the world's largest adult site, revealed more than a quarter of online visitors are now women.
The top search terms they enter include the words "big d***".
Relationship charity Relate has warned online porn is fuelling a crisis in bedrooms, with two in three people saying their sex life is disappointing.
The women have had their hormones nullified and their eggs burnt out by non-native EMF, whilst their male counterparts wander round bent double over their iPhones at ground sperm zero level for similar reasons.
What prozac-pushing react-tards like Jordan Peterson and Stefan Molyneux aren't getting, is that they too are having to imagine normal gender types, whilst the physiological fact is that the whole world is going the same way as Japan, where the general population has no sex left in them whatsoever.
Japan Is Dying: All Work, No Sex Means No Future ... [Link]