because if he pretends its okay, in the past what has happened? have you calle dhim on it? confronted him? dragged him to marrriage guidance? kicked him to the kerb?
or have you sat there wondering how can he do this? if I confront him will he leave? am I being unreasonable? am I crazy? is it me? did it even happen? stuffed it all down and carried on as if it was all okay, eventually.
he has learned that if he ignores it and pretends like it didn't happen, like he didn't say those things and act like a jerk, eventually it will be as if it didn't, he'll get all the same privaleges etc, gets treated like a human being, gets love and attention.
note that I am not saying this is your fault, or that you taught him to be this way. He isn't a toddler, you should NOT have to train him to act like a rational human being, to treat people the way he would wish to be treated, to take account of the feelings of others.
whether he sees deep down that it does you damage or not is hardly important unless you are his therapist and he is coming to you for help. What is important is that he repeatedly does this. and its not ok.