Q I have just discovered that my boyfriend of ten years has been using online sex chat rooms with a view to meeting up in real life, although my discovery means he hasn't had a chance. He argues that he hasn't been unfaithful since nothing has happened, but I feel that he has been emotionally unfaithful. I feel betrayed and he thinks he hasn't done anything wrong. How can we resolve this?

The Times Sex Councellor replies: There is no way that you, singular, can resolve this issue. One of the most galling things about infidelity, whether on or offline, is that you, the person who feels wronged, do not get to decide whether you want to make things right.

No matter how hurt, humiliated and betrayed you feel, you do not have the power to control the eventual outcome of the situation. Your boyfriend does. He gets to choose whether he is willing to acknowledge that his behaviour is a problem, and if he can be bothered to change it. He may have had only virtual sex to date, but the ACE (anonymity, convenience, escape) model of cybersexual addiction - as defined by Dr Kimberly Young, an acclaimed expert on internet addiction - shows that disinhibition, accelerated intimacy, and hypersexual online behaviour are a pretty accurate predictor of real-world transgressions. I suspect you don't know the half of what he has been up to, not that it really matters. Ellen Helsper, research fellow at the Oxford Internet Institute, University of Oxford, says: “Couples do not make a distinction between online or offline infidelity because the emotions, and the sense of betrayal, are the same.”

Helsper recently collaborated with William Dutton and Monica Whitty on an international investigation into the impact of the internet on marital relationships. The results of “Me, My Spouse and the Internet: Meeting, Dating and Marriage in the Digital Age” reveal high levels of agreement between married partners about the unacceptability of online physical and emotional infidelities.

Whitty, who is based at Nottingham Trent University, and is the co-author of Truth, Lies and Trust on the Internet and Cyberspace Romance: The Psychology of Online Relationships, also says that “participants who engage in cybersex and erotic talk online are clear that their behaviour constitutes an act of betrayal”. So I sent her your question.

Whitty describes your boyfriend's behaviour as “emotional betrayal” and says that his “plan to meet the person face-to-face makes this transgression even more painful”. Damn right. Happy couples don't hurt each other in this way. Healthy relationships don't tend to stop at cohabitation either. Long-term relationships have a natural momentum that steers couples towards increased levels of commitment. Whether that commitment evolves as marriage or children or both is immaterial, but the absence of either in a ten-year relationship would ring alarm bells for most people.

It can be really difficult to retain a sense of perspective when you have spent a third of your life with one person, so it may be an idea to share this problem with a close friend or family member who knows you both and can offer you an objective opinion. Counselling is an option but, again, your boyfriend gets to choose whether he wants to engage. And when a woman feels betrayed it can be incredibly irritating to have to listen to a therapist telling you that your boyfriend's cybersexual encounters are a symptom of underlying problems in your relationship, and that to maximise communication you need to suspend your feelings of betrayal and avoid judgmental language in favour of non-blaming statements such as “I feel neglected when you stay up all night reading porn-filled e-mails from strangers”.

Fortunately I have resisted the temptation to trade journalistic independence for a few letters after my name, so without breaking any codes of practice I can advise you to bin your toxic boyfriend and conserve whatever is left of your self-esteem. It is always difficult to walk away after ten years, but I can tell you from personal experience that hanging around for another five doesn't make it any easier.

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