Confused? Okay, here's an example: Let's say the wife has the stability of a relationship with a man she loves a lot. But without the internet, she becomes frustrated over time because she needs more mental stimulation than her rancher husband - and Butte, Montana - can provide. She gets resentful and angry and feels she is missing out on life. Her husband senses this and closes down emotionally and the two eventually divorce. Mom moves to Los Angeles and the poor kids shuttle between Dad in Butte and Mom in LA.
But what would happen if the rancher's wife from Butte, Montana could have online secondary relationships while maintaining her primary relationships with her husband and children? To work, it would have to be open and not a sneaky thing. But if everyone was above board and honest, I see the online thing as the way Sab's proposal might actually become a societal "norm" someday. This rancher's wife might end up having an intimate online relationship with an actor living in New York City, a financial consultant from Japan, and a school teacher from Orlando, Florida. (You could change the example to a male and the people involved could be of either gender.)
With this new internet world, the wife meets other online friends and begins to feel very close and intimate to another guy or guys (or other women). These secondary relationships provide her with the variety and freedom her heart desires. To qualify as a true "secondary" relationship, it would have to become intimate and loving and go beyond neighborly coffee talks. These online relationships could remain "love from afar" or they could include a physical relationship. But I think it could qualify as a secondary relationship without necessarily involving sex.
Using Sab's scenario, this woman has an open honest talk with her husband and they maintain their relationship while expanding their "family" with other nurturing and supportive, intimate, and loving relationships. In this case, the children are in a stable family unit versus an unstable one and the rancher's wife and her husband develop new relationships without the necessity of ending their relationship and hurting their children. Ta-daaaa!!! It works!
Twenty years from now, remember you heard it here first. =)