Oh no: Here's the age you're most likely to cheat on your partner.

Discovering your partner is being unfaithful is one of the most painful experiences in life. It normally comes as quite a shock. You never thought for a second the person you love, who is meant to love you, would hurt you so much.

While researchers still haven’t managed to come up with one definitive reason why people cheat, they have identified the age at which it is most likely to occur.

That age is 39.

A recent survey, conducted by infidelity website IllicitEncounters.com, has found 39-year-old’s are twice as likely to cheat on their partners. The survey also highlighted 29 and 49 as common ages for cheating (there’s something about approaching those ‘milestones’).

The Science of Cheating. Find out why most people cheat. Article continues after this video.

In Australia, approximately 60 per cent of married men and 45 per cent of married women cheat on their spouses, according to the 2010 Australian Sexual Health Survey.

As well as this, cheating website Ashley Madison reported more than a million users were from Australia, a number that placed us third in the world-wide cheating stakes.

So what is it about the age of 39, and to a lesser extent 29 and 49, that makes people cheat?

Researchers Adam L. Alter and Hal E. Hershfield from New York University and the University of California respectively, confirmed the survey’s findings and concluded that these “danger years” are due to a preoccupation with ageing and concerns over the ‘meaningfulness’ of life.

The researchers said these concerns lead to behaviours that “suggest a search for, or a crisis of meaning” such as an affair.

That's also why people who use dating websites often lie about their age; saying they are 25 instead of 29, 35 instead of 39 and 45 instead of 49. There's a definite trend around distancing oneself from significant birthdays.

The data applies to both men and women. Clearly 39 is one birthday celebration that's about to take on an entirely new meaning in most households.

No so much a 'happy' birthday.

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