If you've ever cheated - and, let's be frank - you tend to make a habit of it, you might be able to blame your genes. That's the verdict of New York-based anthropologists who claim people who are serial cheaters may have a particular genetic variation that means they simply can't stay faithful.
Talk about a good excuse for engaging in risky sexual behaviour. But the researchers, writing in the journal PloS ONE, say being unfaithful or promiscuous could be caused by a gene that's linked to the feel-good brain chemical (or neurotransmitter) dopamine. Those who have a particular variation of the dopamine receptor, they claim, are more likely to cheat and be promiscuous than others who have the normal dopamine receptor.
In tests involving college students, 50 of those who had the normal gene. Of course that still leaves more than one in five people without a genetic excuse for being a love cheat, but it also means half of those who do have the faulty gene are resisting their genetic predisposition to be unfaithful.
Or perhaps they're just particularly good at telling fibs.
Perhaps serial cheaters are simply addicted to falling in love, as several studies suggest the feeling you experience when you fall for someone is like taking a drug.
But the big question is, if you could test a potential partner for the one-night-stand gene, would you do it?