Melbourne's Brenton Campbell, who met girlfriend Janice Lai six months ago, was shocked to hear the news.

Sex and relationships, Most women in their 30s want more sex!

"I would have thought it would have been reversed," said Campbell, 23.

When asked to change one thing about their sex life, more than half of women said more interesting sex compared to 15 per cent who said more sex, reports

The kinky study also found that men Down Under were two to three times more likely to initiate sex - except for the over 50s.

A third of surveyed men in their 40s said they had strayed, up from 23 per cent among those in their 30s, the study stated.