How do you define cheating?

Of the many conversations couples need to have before they get married,” or move in together,” comes another one: What role will the Internet play in their relationship and how transparent are they going to be about that?

At least that’s the opinion of Beatriz Avila Mileham, who interviewed married people who used Internet chat rooms for emotional or physical infidelity for her doctoral dissertation at the University of Florida.

“The Internet will soon become the most common form of infidelity, if it isn’t already,” she said.

A lot has happened since that 2003 study, like the iPhone and Blackberry apps unveiled by AshleyMadison.comin 2009 that makes cheating, never too hard to do, even easier (and less traceable).

“So, I agree, it’s a conversation couples must have, along with one about monogamy and how they plan to define what cheating is, and a question that will no doubt be addressed by The New I Do: Reshaping Marriage for Cynics, Commitaphobes and Connubial DIYers, the book Susan Pease Gadoua and I are coauthoring.”

All you have to do is read about the newlywed Indian woman who is divorcing her hubby because he didn’t change his Facebook relationship status from single to married to see that the Internet is rapidly changing how and what we think about relationships and what’s acceptable online behavior for our partners.

Perhaps most of us wouldn’t throw in the marital towel over a Facebook status, but a spouse’s misbehavior on Facebook and other networking sites has increasingly played a part in divorce proceeding, according to a new study by the UK divorce company Divorce-Online, which says Facebook was a contributing factor in more than a third of 5,000 divorce cases. The top complaint; spouses sending inappropriate messages to the opposite sex.

OK, here’s a trick question: define inappropriate.

As I wrote in my HuffPo article, Why Internet infidelity is a growing problem, the Internet and technology like Skype and webcams have made pornography and the possibility easier for everyone, even if all we end up doing is flirting online, and a good 20 percent of us do just that, according to a 2009 report by the Pew Internet and American Life Project.

Is flirting cheating? Sexting? Messaging a hottie on Facebook? Watching porn? Depends on who you ask.We know that a tryst in a hotel room is cheating; the online world is much more ambiguous than that. But it’s clear that Facebook and other social networking sites has made life more challenging for people in relationships, and a sobering study recently published in theJournal of Marital & Family Therapy indicates how ill-equipped most therapists are in dealing with Internet infidelity:

“A majority (73%) of marriage and family therapists did not believe they were trained in how to deal with this problem. These findings accentuate the need for therapists to be well-informed when working with clients in which Internet infidelity is an issue.”

Part of the problem is that few of us, including therapists, can even agree about the definition of Internet infidelity. Some say there has to be some sort of real-life sexual behavior to be cheating. Others say emotional intimacy is enough.

“One question the study raised was gender, not only of the client but also of the therapist. Porn watching appears to be accepted, perhaps even expected, among men. But some found the reverse to be hard to grasp; according to one therapist, if a husband considered his wife’s porn habit to be infidelity, I think I would be flabbergasted. If a couple came in and the husband said, ‘I am feeling, you know, terribly hurt. My wife is watching porn,’ I don’t know what I would do. I think I would call the state and hand my license in.”

That attitude is problematic since 30 percent of women watch porn online.

The study indicates therapists have their work cut out for them if they’re going to be helpful to couples facing Internet cheating. Some believe both partners should have total access to each other’s social networking sites and email sites to build accountability. Last year, a Connecticut judge ordered a divorcing couple to exchange passwords for their Facebook and dating websites. That seems incredible invasive, but perhaps more couples will be forced to do that in future divorce cases (which may send more people who want to cheat to AshleyMadison.com apps). All of which means as long as people want to cheat, there will be new technology to help them do it.