Because actions speak louder than words. You should know that by now.
If your ACTIONS don't back up what you are saying then why bother?
This porn issue adds a totally new element to your situation and now it makes more sense.
Would it be enough for you if your W simply told you she wanted to be with you while sleeping with other men?
You pressure her way too much, you say mean things to her then expect her to accept what you say and then get frustrated when she doesn't. I don't get it.