Like I said, until you have been in a comitted relationship for a considerable lenght of time and in which you have invested a significant amount of your life, finances and feelings and anything else you can think of then you haven`t got a clue of what you are talking about. Sure, its easy to say if someone you are only casually dating or seeing cheated on you that you would dump them asap, anyone can do that, but its not quite so simple when you live together are married and have kids as well and share property and other things. Your simplistic view of what is a very complex issue shows your immaturity and lack of experience in regards to relationships in general.
I would have to agree not so simple the older you get or the longer you in the relationship the more complicated it is aswell.
Those bonds are significant that you build and maybe the reason why some couple reconcile after a spouse cheated becuase those bonds are strong enough...
I for one would seriously consider a file for divorce but it would take painstakenly critical soul serching to make sure that its the right decision....
And if I were to do the divorce it would be on my grounds i.e no spousal maintenace take almost everything etc etc....
If if i still had to pay spousal maintenace and supply a lifestyle to the spouse i would stay "leagally married" but I would be single and baisically she'll be a roomate.... Now im saying this because kids aren't involved if they were even more of a deilemma....
I dunno not an easy one