Seven-years has traditionally been the time when love and affection give way to disillusion¹ and disappointment.

传统观点认为，“七年”是婚姻的一个坎，结婚到了这个年头，爱情渐渐变淡，取而代之的是幻想的破灭和失望。

Relationship threat: The majority of couples who divorce have spent more than a decade together, a study has revealed.

But couples who manage to survive the seven-year itch²（痒，疥疮） would be wise not to get complacent³（自满的，得意的） .

The biggest threat to modern marriages actually comes from the 12-year itch, research has revealed.

The majority of couples who divorce have now spent more than a decade together before going their separate ways.

And they are increasingly likely to cite 'growing apart' or 'falling out of love' as the cause of their split.

There has been a four-fold increase in couples breaking up for these reasons in the last two years, amid increasing financial strain（资金紧张） on families.

But infidelity（背信，无信仰） is still responsible for more than a quarter of divorces. The seven-year itch - or the theory that adultery（通奸） becomes impossible to resist after seven years - got its name from the 1950s film starring Marilyn Monroe.

The study by the Grant Thornton accountancy group, which was based on a survey of 90 of the country's biggest family law firms, echoed figures released last year which showed that marriages are most likely to fall apart around the 12-year mark.

Sally Longworth, of Grant Thornton's Forensic⁴ and Investigation⁵ Services, said: 'This rather dispels⁶（消除，驱散） the age-old myth about marriages failing after seven years.

'It is impossible to put any scientific reasoning on why certain marriages succeed and others fail.'