If we are going to start quoting statistics from the "reliable" internetz, the fact of the matter is the data isn't there. Much of it is very outdated (1970s), and finding people involved in these types of marriages is difficult. There are even issues with defining what constitutes an open marriage.
Plenty of people are not going to broadcast their personal info from which most of society is going to judge them negatively. There can be serious repercussions leading to loss of employment and losing custody of children. It's not due to being "ashamed". My open marriage is "out" to my family, but certainly not at my place of employment. People are very conservative in my field and my sex life isn't really anyone's business but my own. Unless I go looking for the few studies that are out there, they won't find me. I'm far from the only person in our society that isn't readily volunteering for the little bit of research that is available.
There seems to be much back and forth about who knows someone with a failed open marriage. I've been with my husband (he's not the one who cheated on me) for 14yrs in an open marriage. I'd say that's more than the average length of a marriage. I know of 4 couples in our community that have been married for over 20 years. I've also seen a couple of divorces as well. However anecdotes don't count as data with the big picture.
My relationship style does not go against my "women's nature", nor do I have problems sticking to any agreements in my relationships when put in "tempting" situations. I'm quite happy with my relationship with my husband and my boyfriend. They are as well. I don't judge monogamous marriages, or the many other types of marriages that go on in other cultures. If you don't believe in open marriage, don't have one.
No one deserves to be hurt by infidelity, and I think it's pretty crappy, petty, and judgmental to say that to anyone. The general public doesn't usually have a clue how these relationships work, yet feel free to judge and act morally superior. Being judgmental isn't a quality of having superior morals, by the way. It's the very opposite.
What I have found on SI is that infidelity works the same way in both monogamous and open marriages. The waywards follow the same playbook. The hurt in both types of marriage is devastating and life altering. The steps for healing are the same. The info and advice given here are valuable for any type of marriage.
[This message edited by Rubyred at 11:23 AM, April 12th (Saturday)]