Many experts believe that the arrival of the internet has made cheating easier, and it is certainly true that email, chat rooms, discussion boards and social networks such as Facebook and Bebo have provided many new ways for people to communicate and meet each other. As a result, internet infidelity is increasingly being cited as a reason for divorce and is causing problems in a growing number of relationships.

Some people argue that most internet activity is harmless - often it begins just as two people talking to each other. It is true that while a small number of people go online specifically to find sexual partners, many, cyber-relationships begin as  genuine, innocent attempts at friendship. However, intimacy can develop so quickly online that many are shocked at how soon an online relationship becomes sexual. Experts maintain that if you are spending time online with another individual of the opposite sex, discussing personal details, perhaps even flirting or conversing with sexual undertones, this can be defined as a cyber affair.

Communicating online allows intimacy to build very quickly. When people cannot see who they are talking to, and know that they in turn cannot be seen, they are less likely to feel judged. As a result, people are more likely to reveal personal information much earlier than they would in a face-to-face situation.

The blossoming cyber-relationship begins to take the individual's attention away from his or her family and relationship, and they share a growing private friendship. Barry's wife, Stella, began communicating regularly with an old boyfriend. He recalls "It all seemed so harmless at first. She had got in touch with quite a few old school friends and it was a nice way for her to stay in touch with everyone as we live a long way from our home town. But pretty soon I began to feel excluded from this part of her life. She began to spend hours online every evening, with the excuse of bringing work home from the office, which she'd never done before. Then she began being quite secretive and I realised there was much more to it than just getting in touch with old friends." As Barry found, chatting and emails may lead to exchange of photographs, telephone calls and finally meetings, until the couple's cyber relationship evolves into a real-world affair.

If you suspect your partner is cheating on you with someone online, you should begin by gathering as much information as possible. For example, if your partner is using the computer, wait until they leave the machine idle to go into another room, then hit the 'back' button to check on what they were last up to. Scrolling through the browser history will also give you an indication of chatrooms, social networking or online dating sites they may have visited. Other possible signs of internet infidelity include switching screens when you enter the room, demanding privacy when on the computer or spending a lot of their leisure time on the computer (unless they are an online game fanatic of course!)

If you are fairly certain that you might be a victim of an Internet affair, technology can work for you, helping you to gather hard evidence before confronting your spouse. The following steps will help you to get started:

1. Try to get passwords that your partner uses for email and any social networking sites. Check their email files and networking pages. You can find out which sites your partner has visited by checking their browser history. Be aware that many people use the same passwords for all of the sites they visit so you may also be able to find other sites that your partner is a member of, possibly including dating sites.

2. Check the temporary Internet files and history log on your computer. The history will also tell you whether your partner has set up an additional email account which may have been set up to contact others online. If they have set up a secret email account, set one up yourself, email your partner posing as someone from a dating site or networking site and wait for their response.

3. Install key-logging software onto your computer. This is especially helpful if your partner is computer-savvy and likely to clear the temp and history files after he or she has finished surfing. In some countries such software is only legal if you own the computer so check your legal situation carefully before you buy and install this software.

If you feel that Internet friendships are beginning to have a negative impact on your relationship, talk to your partner about restricting the time you both spend online. Consider restricting Internet usage to business or personal emails to friends; for example, you might agree that neither of you will go into chat rooms or use social networking.

This is an edited extract from our ebook, Signs of Infidelity.  Available for immediate download.

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