Young men are accused of being part of the reason why New Zealand has such high rates of the sexually transmitted infection, chlamydia.
Cases number tens of thousands and have been increasing for a decade.
New Zealand's rates of clamydia are said to be double those of Australia and Britain.
The Environmental Science and Research Institutue provides an annual surveillance report.
Family planning clinics provide anonymous data to help with surveillance of sexually transmitted infections.
But chief executive Jackie Edmonds says despite attempts at sex education, in practice the same difficulties continue.
She says people are not using condoms when they should and both young men and women need to understand the ramifications both in terms of their own sexual health and pregnancy.
More can be about New Zealand's high rate of sexually transmitted infections on Insight on Sunday.