I also don't think you did anything wrong. I've also felt attacked in this forum, so I think it's best to take the approach of keeping an open mind, taking what's helpful to you, and leaving the rest.
I'm so glad that you came here to vent and didn't say anything to the cheaters.
Of course they are miserable people who are trying way too hard to appear to be good, loving people. And they see any intrusion by a real, loving person into their life as a threat. You know what they really are, so they have to work extra hard to keep up the facade.
HOWEVER, it does seem at times that you are letting things bother you way too much -- which only impacts you. (This is true for almost everyone, including myself.)
I frequently have to go to various speakers for fundraising lunches/dinners/affinity groups, etc., and while I mostly think they are a waste of time, I went to one last fall that really helped me to change my mindset. It's super easy to remember. The class was called Accept It or Change It."
Essentially, when faced with a stressful or unpleasant situation, you have three choices:
1. Accept It
2. Change It
3. Be Miserable
In cases where you can't change things (i.e. dealing with assholes), you have to figure out if there is a way for you to change your actions, to accept the situation, or whether you just want to be miserable. Being miserable is the worst choice you can make!!!
Getting to acceptance isn't easy, but it will improve your life.
Imagine how much more pleasant your day would have been if, instead of getting pissed, you thought something like, "What losers they are! So insecure they're threatened by some snacks! Ha!" and then did some yoga or deep breathing exercises. Or maybe a kickboxing workout :)
I know it's so hard to detach -- it was hard for me, and I could go true NC since no kids with XWH. But you will be in such a better place when you can get to "meh."
I know you can do it!!!Me: BW, divorced, now fabulous and happy!
Married: 11 years, no kids
Character is destiny