Women and men definitely find certain things attractive because of the whole survival of the fittest thing. But, I still believe women are more monogamous (in general) than men. I don't mean to man-bash at all, it's just what I believe to be true.
In terms of open-marriages, it's because of that love and commitment that the compromise happens. There are many reasons for this, sex being the top of that list and while love and commitment should be the most important, sex is also important in a relationship. An example we may be able to better understand is those who fall in love and marry someone that's not into tickling. Tickling is an important part of most of our lives and can make things complicated in the marriage if the other person is unwilling to experiment with it or whatever. If the love and commitment is there then that compromise that the person in question can play with others may come about.
Two wrongs don't make a right, and I realize that I was in the wrong in cheating on that person. It was a pointless relationship that should have been ended sooner than it did. Thank you for your input on that.
Serious dating and marriage, in my mind, are only differentiated by ceremonies, last names, and pieces of paper. I see relationships differently than most people, I guess, in that when I start to become serious about someone, I do everything I can to make things work. I like to stay with whoever I'm dating for as long as possible as I am not fond of the "dating around" thing.
The "marriage is the leading cause of divorce" was both a joke, and a pointing out of the fact that close to half of marriages end in divorce, albeit almost 25% is people in their early to mid 20s.