Last year, in all the reading I was doing, I came across a book about covert passive aggressive narcissists that had a chapter on sex and the narcissist.
Your descriptions are pretty typical.
Here was my takeaway:
They may drop innuendos, but they rarely, if ever, initiate. They take no responsibility for the encounter, often expecting to be taken care of (almost like a child-yuck). They expect to get what they want out of it, so that can be their own pleasure, or if that doesn't work out, they can just flip it and let you know how inadequate you are as a partner. Abusing you emotionally is a good hit for them too.
Intimacy is so easy for them to weaponize, especially if they have a spouse that craves that connection and closeness. It's a potentially huge source of control and emotional abuse.
What you did in regard to porn isn't even worth mentioning in many people's books (mine included), but put a hash mark in your column if it makes you feel better. But how many hash marks are in her column for inappropriate things she did?
Mature relationships communicate and take the other person's feelings into consideration. With narcissists you don't get that. They seek control in all things, and maintain it at all costs. If they have you like a puppet on a string, then they're feeling like everything is okay. Intimacy is just one more area where good communication and give and take should be true, and a very important one at that. When are you ever that vulnerable with another human being?
There's a lot to heal from in this kind of mess. You definitely deserved more consideration, and you didn't do anything wrong or destructive. You're a healthy and normal guy who did something many very good men do regularly. So you left it there intentionally - sometimes something's got to give. Maybe that was just the point where you started taking your own power back.