Embarrassing, out of touch, and too late: That's the blunt assessment of sex education classes by school students around the world, including Australia.
A review of 55 studies of young people's experiences in sex and relationship education (SRE) classes has found little improvement in the quality of teaching during the past quarter of a century.
Many teachers are ill-prepared to teach such a specialist subject, while students are simply embarrassed to be there.
Students in mixed sex classes often feared being humiliated, with some boys reluctant to ask questions for fear of revealing their lack of experience.
While girls often took the classes seriously, they risked being harassed by boys if they were involved in discussions about sex.
Many of the students, most of whom were aged between 12 and 18, disliked how the classes took a scientific approach to sex, the "unrealistic" focus on abstinence, and negative portrayals of teen pregnancy.
They also believed that sex education classes were delivered too late and that there should be more information about homosexuality, same-sex relationships, pleasure and desire.
And they wanted specialists to teach them because their own school teachers were too poorly trained and risked complicating the teacher-pupil relationship by providing information and advice on such an intimate subject.
While the findings were based on studies of students in the UK, Ireland, Australia, US, New Zealand, Canada, Japan, Iran, Brazil and Sweden between 1990 and 2015, the results were strikingly consistent, the study's authors said.
"The synthesis indicates that schools take insufficient account of the 'specialness' of sex as a topic, negatively affecting the way SRE is delivered and rendering many young people vulnerable and reluctant to engage," the Bristol University researchers wrote in a paper published online by the British Medical Journal on Tuesday.
The researchers added that while young people wanted a 'sex-positive' approach from their lessons, it was essential that schools address the issues about who teaches them and adequate training.
"Unless we get the delivery right, young people will continue to disengage from SRE and opportunities for safeguarding young people and improving their sexual health will be reduced," they said.