I have to tell you that I am far from really "getting" this whole idea of boundaries myself but IMO it is more a matter of how you emotionally react to a situation or behavior from your spouse rather than anything you do or say.
This is why the boundary concept eludes you. It is NOT about how you react. It is about how you feel about yourself. You are whole, complete, self confident in yourself, without any need for confirmation or validation from anyone else. The CENTRAL tenant to this is your SELF INTEGRITY. If you know there is something about you that is wrong, say jealousy, then by being true to yourself (for all you religious readers out there) you will fix that flaw. And in so doing, you know that you are a good person, no matter what your spouse says. If he says you are not, it does not bother you because you KNOW you are. You know this because you are TRUE TO YOURSELF.
Just acting in the proper manner does not mean you have believe in how you are acting. In fact, acting contrary to your belief (i.e., not being true to yourself) means you are choosing this particular behavior because you think it is what someone else wants to see. So what happens if they decide they want to see something different. Always chasing their whims makes you a puppet on a string. What really triggers the anger is the fact that you have done this to yourself. The self blame can be so strong that some people refuse to accept their own responsibility. So they blame the other person for changing whims, for “making” them do this or that. The fact is no one “made” you do anything. You choose to do as you wish. You choose to be the puppet.
This is what Corri is trying to tell everyone. Sometimes it is hard to understand the message, so I hope this helps.
