Internet cheating is not just about spotty students plagiarising essays. Research by the US Fortino Group suggested that one-third of divorce litigation is now caused by online affairs. Here in the UK, a poll of 51,000 people suggested a shocking 51% had had an online affair. However, 68% of these didn't class internet cheating as infidelity.

I first came across internet cheating 10 years ago when my friend Sara bought a computer. Her boyfriend was unemployed and quickly began to spend all his time on it, even when she was at home. He eventually confessed that he had been carrying on an intense virtual affair with another girl. She kept the computer, but binned the boyfriend.

One of the difficulties with internet cheating is how easy it is to do, from the convenience of one's own home, while your other half is watching 'Desperate Housewives'. 'Technology is providing the opportunity for conducting relationships differently in today's society,' says Relate counsellor Denise Knowles. 'Affairs conducted on the internet are a bit like having the 'other' woman/man under the same roof which further compounds the sense of rejection and betrayal.'

With 200 new chatrooms a day, and websites specifically designed for cheats, internet cheating can go far beyond the virtual and into the bedroom. Ruth Houston, founder of InfidelityAdvice.com and author of 'Is He Cheating on You? – 829 Telltale Signs', explains.

'In one survey, 29% of the men said they go online specifically intending to cheat. Studies show that one in five men claim to be single when they're not.'

Many people who indulge in an online flirtation don't consider it to be as serious as looking for sex online. Ruth says one of the reasons for this is the differing attitudes of men and women.

'Since, in the early stages there's no sex involved, men don't really consider a cyber affair to be infidelity. A 'Divorce Magazine' survey found that 46% of men considered an internet relationship to be infidelity, compared to 72% of women.'

My husband spends a fair bit of time on Volkswagen and Vauxhall websites. It has never really worried me as, truth be told, I am the flirtatious one in the partnership. More than that, I trust him. But if you did discover that your chatroom-loving man was carrying on a virtual flirtation, how bad would this be?

'Cyber-cheating is a form of emotional infidelity and most emotional infidelity eventually leads to sexual infidelity,' says Ruth. Her research has found that as many as 31% of people who had an online flirtation eventually had sex with that person. Perhaps I should keep my eye on him then.

If you are worried that your own man might be an internet cheat, you could start by asking yourself these questions:

Is he on the computer until late into the night? Does he head for the computer first thing in the morning?

OK, so most of them do that, but add to that these questions:

Does he insist on privacy when surfing the net? Has he moved the computer into a private area of the home or a locked office? Is he constantly changing the access passwords?

If you discover your boyfriend is carrying out what he considers to be a harmless online friendship, start by asking if you can watch him while he writes. If he refuses, you have to ask yourself why.

Tasha Joseph is the creator of the phenomenally successful website, Dontdatehimgirl.com, where women are invited to name, shame and post photos of cheats on the internet. She suggests more devious ways of catching a cheat:

'My advice to women who think their man might be cheating on the internet is to first gather evidence and find out what he's doing. You can do this by installing spyware like Spector on his computer and checking out who he is emailing and the sites he is visiting while online. Once you get the proof of infidelity, I advise women to move on and find a fabulous guy who will love and cherish them and of course, be sure to warn other women by posting the cad on DontDateHimGirl.com!' Take care though; Tasha is facing her first lawsuit from a disgruntled 'star' of her site.

At the end of the day, most of us trust our partners and most of us, men or women, know where flirting should begin and end. Dr Reena Sommer, author of the ebook, 'The Anatomy of an Affair', has this to say:

'Rarely do affairs come out of the blue. In most cases, they are not the cause but a symptom of a relationship that is flawed. Generally, relationships that are mutually loving and intimate and based on valuing, caring and respect are not susceptible to infidelity.'

Try to keep this in mind, before you do something you might regret, whether this is checking up on your boyfriend, or going into a chatroom yourself.