yosemitebabe:
Thank you for expressing my opinion better than I could.
Having been around the block a few times, this is my take.
Both parties in the committed relationship and the third party are equally responsible/irresponsible for the affair.
Why? Because in most cases they are all acting on instinct rather than thinking rationally.
As surveys have shown, the first things a man looks for in a potential mate is good looks and a willingness to have sex. Women look for evidence that the man is a good provider and is strong and smart enough to survive.
These are the same traits that cave people looked for–and for the same reason. Instinct tells us to.
Trying to ferret out reason in affairs of the heart is a lost cause. Too many people don’t think first. They just act and then rationalize their actions after the fact.
We must simply face the fact that too many people just aren’t as rational as we are (I figure most of you 'Dopers are eligible for the club).
I was gonna post here, but as zev has more or less done it for me, and far too many are too busy hunting trolls, I see no reason to do so. 
Cheating: Been there, done that.
Pro: Good Sex
Con: Divorce, loss of property, loss of money, alienation of child, loss of self respect, sorrow, sadness, loneliness, clinical depression, failed suicide attempt, years of therapy, and who knows what will surface in the future.
Conclusion: It was my decision to cheat and therefore my responsibility. I violated my promise, I broke my word–I sometimes wish I could find someone else to blame it on.
And the woman I cheated with? While having an affair with me, she was also having an affair with another guy. He divorced his wife, she divorced her husband, dumped me and married him. Two years later, she called and asked me to meet her at a motel. That time around, I had the sense to decline.
But I am feeling much better now.
After reading Tomndeb’s post in this thread, I must admit that I have been given pause for thought with regards to my own assertions. I was struck by his candor and his willingness to share with us a very personal slice of his life. His reply to my contentious post, dipped in generalities more than specifics, was indeed civilized and, I am not ashamed to say, quite a propos. Ezra Pound, the noted poet, made a tangible point when she said: “Any general statement is like a check drawn on a bank. Its’ value depends on what is there to meet it.” I need not say more.
Cue the Mormon Tabernacle Choir.
Let’s face it. The richer the guy is, the more women will shamelessly pursue him. I mean, do you think it’s Donald Trump’s LOOKS that attracts beautiful women?? I know that men are very physical beings. And I must say that I’m GLAD my husband isn’t filthy rich, or a high profile celebrity or athlete. Because no matter how nice the guy is, being relentlessly pursued by attractive people must be very, very difficult.
I’m not saying it’s an excuse for indecent behavior, but you’d have to be made of stone to resist constant temptation. I mean, Bill Cosby even had an affair, and he seems like a pretty decent guy.
So, yes the responsibility is with the man to keep his vow. But it would be a lot easier to do so if we were surrounded by decent women who respected the institution of marriage.