Is cheating no longer considered immoral?

Today on the Drew Mariani Show, one of the topics was the incidence of infidelity. A recent study (of dubious reliability, according to one guest, but it doesn't detract from my point) suggests that about half of all people cheat on their partners at some point.

The question was raised, then, "If everyone's doing it, is it even immoral?" The answer is yes, for a number of reasons, a couple of which I'll only touch on.

First of all, morality is not determined by how many people hew to it, or how many dismiss it. Secondly, if you're still calling it cheating, you probably still have a sense that it's wrong, so trying to argue that infidelity is okay because cheating isn't bad just shifts the problem.

If people walk into relationships expecting their partners to fool around with other people, knowing their partners expect the same, then, true, it's not necessarily cheating, it's just following the conditions of a more libertine arrangement; however, the problem is that when people get married, they do make vows to the effect of "forsaking all others"--putting the spouse first in all things, and not sharing with others what is promised to the spouse.

If people walk into relationships expecting cheating, infidelity isn't the problem. (Okay, it's a problem, but it's missing the point.) The problem is people not taking vows seriously, not making them seriously. Don't expect to remain faithful? It's sad, but at least you're honest. Promise to be faithful anyway? Then you're a liar and a hypocrite.

If your integrity is in question, you can hardly be expected to judge infidelity to be moral or or not.