In my opinion, many people who play the "don't be judgmental" card are really saying that they want carte blanche to do whatever they want,
no matter the consequences for someone else, and not be thought of badly for doing it.
The whole "judge not, lest thee be judged" thing needs to be looked at critically. Yes, it needs to be judged.
Accusing someone of being judgmental tends to produce a knee-jerk reaction, like accusing them of doing something "politically incorrect"... I like to think about whether things are
correct, rather than
politically correct.
If we didn't ever judge peoples' actions, anyone could do nasty things to others and not suffer peoples' disdain. If we always judged peoples' actions, we'd never get anything done and our lives would be poisoned by constant sniping.
The answer is that there is a middle ground, a line to be drawn. Everyone must find that line for themselves. What criteria do we use? There are many. My favorite is the Golden Rule. More generally,
do my actions have negative consequences for someone else?
Is it bad that I have a house that's way too big for two people? Is it bad that I take long showers and use lots of heat and water? Is it bad that we use fresh water and chemicals for our lawn? "Yes" is the answer to all three of those questions and others. My actions have indirect consequences for others. But I draw the line somewhere past those actions on the "wrong" scale. They are wrong, but I don't change them. Others may judge me for them.
Your friends are well aware that their actions enable someone to do things which will have bad consequences for them... worse if the wronged wives find out. Just because the husbands' actions are worse than your friends' actions doesn't mean they get off the hook. Because of what your friends do, bad things can happen. Bad enough that they are on the wrong side of the line.
I don't see anything wrong with "judging" their actions... in fact, not doing so is abdicating responsibility, which is what they themselves are doing. They are asking you to throw in with them, to validate them, by not caring about the consequences of their actions to others.
Why do people fall for this? Seriously, why do they?
No one has to tell your friends they're going to Hell or anything... just that what they are doing can hurt others. I'm not a Christian, but I do believe you can love someone and still dislike some things that they do. Sometimes we turn a blind eye. Sometimes we shouldn't.