He continues to HURT me but yet he's so blind to see it

Men, why is it so hard to read them? What makes them so darn good at hiding their true intentions and/or feelings? I've been with the same guy for almost three years and still to this day it's so hard for me to read him or even get a little truth out of him(then again maybe that's just me assuming things). Here is the issue I keep running into with my boyfriend. He has this ex girlfriend of his that he has A LOT in common with and it seems to me that he likes,no not like, LOVES her company more than he does mine. I get it, I'm not really into a lot of things that they both are into and I'm not really familiar with all of the jokes he now and than would tell and yet somehow she would always gets. It cuts me deep every time I think about all the things he said and would say every time I asked him in the past about how he truly felt about his ex. She was perfect for him is basically what he was telling me, and I in the other hand was just someone he once fell for and now came to realization that he doesn't(and again that could just be me). When will he open up to me like he did and does with his ex? Why is it so hard to talk to me about things that he does and did with his ex? Is it me doing all the wrongs in the relationship? Do I care too much? Am I just not enough for him? The answer is I will never know for I will never truly get any true feelings or even a bit of the truth from the man I love and in hope that he feels the same way towards me. Why do I keep staying with him if I he continues to hurt me? well the answer to that is simple. I'm a woman in love and he makes me happy even though he chooses another female over me. Does that make me sound insane? Yes, but at the same time I am being a human being who is trying to learn all there is that the hard road to love has and is throwing at me. He doesn't see it but he hurts me every time he thinks, messages, or even looks her up, or simply unblocking her on his social media apps. The hurt continues because I truly found out a week ago that no matter which one of them would message the other, one of them will always reply. No matter if they do or don't have a partner, they would go out of their way to see to it that one of them knows that the other is always thinking of the other. My heart cries tears of blood tonight knowing that he'll always choose her over me.