I think you missed the point. We live in a sex-addicted culture. Sure, men and women had affairs before Internet porn and chat rooms, but the Internet has made illicit fantasy so much easier. The Internet has taken porn out of the seedy sex shops and brought it directly into the home. Affairs begin in the mind. I'm no expert but I could understand how after a while the fantasy would get boring and men and women would want to start looking for the real thing.
No, I get the point, I just think it's stupid.
Look, generally speaking, people have affairs for one reason: people like sex. Sex is fun, it's exciting, and it feels good. People like new things, and that hasn't changed since people have started walking this earth. People are programmed to procreate. We are programmed for sex.
The Internet hasn't made the fantasy easier; people had imaginations before the Internet. Before the Internet, if a man saw an attractive woman in a short skirt or whatever, he still had "illict fantasies." That's just the way it is. After all, even if you want to think that the Internet is "responsible," illicit sex doesn't just magically appear on your computer screen--you have to seek it out, and that idea has to come from somewhere--and that somewhere is the mind of the person who had that fantasy or thought before ever logging on.