This is an issue of expectations.
I totally agree. The thing I have found is that sometimes when a person has expectations, they get them mixed up with "the way it is" - reality. They mistakenly assume that everyone sees an issue the same way, and that "common sense" should lead all people to the same conclusion.
A lot of times, people do not realize they have made this cognitive error until a situation like Mahogany's brings it to light. And now she is trying to address it, so she can logically answer her husband's question, and they can communicate about it. She may find that most of what she thought she was originally concerned about is moot.
There is nothing wrong with having expectations as long as all parties are in agreement. But that takes communication beforehand.
Now, when I run into an unexpected situation, my first reaction is, "What did I miss?" I question myself, my understanding of the situation. Unfortunately, it seems that when most people find themselves in an unexpected situation, their default reaction is to find someone to blame, and that applies to far more than polyamory.