We’ve seen this topic on threads before, but the thing that everyone seems to focus on is mens’ desire to stray. I don’t think anyone would argue that that desire is there. The issue is straying after (a) a guy promises someone that he won’t and (b) that other person has taken significant action based on that promise (i.e. marrying the guying, having kids with him, foregoing work opportunities, etc.).
If you don’t want to be faithful, don’t promise someone that you will be. If you promise someone that you will be faithful and that person relies on the promise, you need to live up to it. Really a pretty simple analysis.