The seven-year-itch theory may well be a myth, for a new survey suggests that marriages go stale after ten years and 11 months.
A quarter of those questioned said their marriage has lost its sparkle because they no longer bother going out together or make romantic gestures.
One-fifth had lost interest in their sex lives, while 12 per cent could not remember the last time their partner paid them any sort of compliment.
The study of 3,000 married people shows six in ten often feel they need to be reminded why they married their partner in the first place.
"It takes a special someone to step back from everyday life and realise it takes a bit of effort to keep the romance alive," The Daily Mail quoted a spokesman for the dating website, as saying.
"And the fact our couples mentioned their sex life not once, but three times in the top ten list indicates this is one area which falls by the wayside after several years of marriage."