It has gotten to the point were very few people stay faithful in a marriage.
From my experience from family, friends, co-works, neighbors or just people I know casually maybe 20% don't cheat.
I don't think man was meant to mate for life, geese yes, man no.
Makes no sense for man to do so. He needs to spread his genes after all.
Now with women working and being so independent it's easy to start a romance, office romance especially since we tend to spend more time with our co-workers then our spouses.
When you are at work you also tend to point your best foot foward, no belching or farting no yelling or being late or rude. Just nice and perfessional and funny. You look good, no house coat or slippers, tie and suit for some and dresses for women so yea I can see how easy it could be for some people and have seen it first hand it fact.
Is it right, don't know. I am not involved in their marriages so I can't say I don't think it is all that bad, like I said I don't think man was meant to just have one mate.