For the infidels among us, it's not always just a quick pash and dash either: one in seven revealed they have been part of a long-term affair. Twenty-six per cent of those were from Palmerston North.
Those who admitted to an ongoing secret relationship were also more likely to be aged 60 or over, unhappy with their sex life and the frequency in which they were able to get busy.
So how much can you really trust a sexual partner in the first place?
Research shows that one in five New Zealanders will lie about the number of people they have had sex with if they deem the lie beneficial.
What leads someone to an affair?
New Zealand-born sexologist and author, Dr. Shelley Hiestand, said a leading cause of infidelity is unmet sexual needs.
"If one partner has needs and desires which are no longer being met, they have to find other ways to meet them," Hiestand said.
The survey results back Heistand's claims, showing 44 per cent of people believe fatigue is the most common hindrance in their sex lives, followed by sexual incompatibility and stress.
Respondents who listed stress as having a notable negative influence on their sex lives were more likely to be aged between 40 and 59 years old and living in Auckland.
Dr. Shelley said while it's common for people to encounter obstacles in their sex lives, there are always ways to alleviate them.
"Fatigue, incompatible libidos and stress would definitely be the top three reasons I hear from clients. However, I would say that incompatible libidos is even more of an issue and can be addressed if the couple is willing," she explained.