Who is more unfaithful men or women?

Think men are the unfaithful sex? A study shows WOMEN are the biggest cheats - they're just better at lying about it.
Are men or women more likely to cheat? While men have always had a worse reputation for being unfaithful, recent studies show that women are catching up fast - but we are a lot more likely to lie about it, and a lot less likely to get caught.
Simply put, it seems that women are better at having affairs than men. According to Dr David Holmes, a psychologist at Manchester Metropolitan University, women are having more affairs than ever - recent studies say the figure is around 20 per cent for men and a bit over 15 per cent for women - but they behave very differently from men when they cheat.
'The biggest difference is that women are much better at keeping their affairs secret,' he says. 'If you look at the studies into paternity, even conservative figures show that between eight and 15 per cent of children haven't been fathered by the man who thinks he's the biological parent.' 

Does she feel guilty about the affair? 'Not so long as Adrian doesn't find out. You know the 11th commandment: don't get caught.'
Women have always had affairs, but over the past 20 years that number has risen dramatically.
Jobs outside the home - with the ready-made excuse of working late or business travel - financial independence and changing social attitudes mean that modern women simply have more opportunity to meet other men and start affairs.

Mobile phones, internet chat rooms and email also make it easier to fuel intimate encounters. 

But while women's lives and sexual behaviour might have changed, their willingness to be honest about it hasn't.
The truth is that we have always lied about our sex lives. British men consistently claim to have had more partners than women - the current average is 13, while women claim to have had only nine.

Plainly, someone is lying here. While men might exaggerate their sexual conquests, the bigger liars are women. 

When studies about sexual partners or fidelity use a mixture of face-to-face interviews and anonymous computer questionnaires, men will give the same answers to both, but women will report much higher numbers when the answers are anonymous.
Why do women lie? Because we must, and because we can. In spite of apparent equality and a more sexually open society, we are still more harshly judged for our sex lives than men.