Boyfriend’s mom

So my boyfriend was married previously, he dated her on and off for a few years and their marriage lasted less then a year. After divorcing her, He moved on rather quickly to me, and his mom absolutely hated me from the beginning. Like threatened to pretty much ban him from the family for dating me, which they did stop talking to him and I was all he had for a good amount of time, and calling me every name under the sun. I’m younger, by a decade. However we’ve been together now going on two years, and while she has tried to patch things over with gifts and dinners out together, I’m more than apprehensive about just blindly forgiving and being super warm and lovey. Also, I know I shouldn’t, but on occasion I’ve looked at his ex wife’s Facebook and seen that his mom still likes and comments on her stuff. I know I shouldn’t be even looking but come on. If she really wants a good relationship with me, why on earth would she still obviously be in contact with her. It’s frustrating because while my boyfriend has an amazing relationship with my family, my relationship with his is rocky at best and it does bother him. I’m just feeling a little lost. I want a good relationship with my in laws. But it feels like it’ll never be what I’ve wanted.

Edit: I understand that yes I am dating him. But both of us come from family oriented upbringings so to us, yes you are dating the family too.