It was a very delicate balance which had to be right, he said.
Fewer than one in five people surveyed felt that shaping attitudes to sex was the sole domain of parents.
Politicians on both sides of the spectrum agreed that sexual education needed an overhaul, though there was disagreement about who was responsible for giving teens a more holistic education.
Conservative Party leader Colin Craig said parents should be responsible for teaching kids about sexuality, but there needed to be an institutional backup if parents failed.
Post Primary Teachers' Association President Angela Roberts said the poll result wasn't surprising.
"A really good place for kids to learn this stuff is in schools where they can be taught by specialists."
However, Ms Roberts said any changes to sex education programs was the responsibility of the individual school's board of trustees.
Parliament's health committee reported last month that sexual education in New Zealand was patchy, outdated and often non-existent.
Committee chairman Dr Paul Hutchison said most of the public would "come on board" when they witnessed the effect of education on reducing abuse, unplanned pregnancies, STIs and abortions.
- Additional reporting: Ben Irwin