I understand that, Bones.
If his mother was a decent person (at ALL -- which most old mothers would be, compared to the one you got) ... it must break your heart to NOT be able to experience some of the sweetness that is built in to connecting to, and then letting go of, an old woman at the close of her life.
Remember--he is not you. He has had a completely different experience in his head about his mother. On the outside, it does look cold and detached, that he seems so unaffected.
It's possible though, that he's just confused. Doesn't know what to feel and/or is having trouble accessing the feelings he does have (in there somewhere).
Do you think you're grieving the IDEA of a mother?
I can so imagine why this is causing a lot of pain for you...
It's not really her, or really him, though, is it?
His inner soup...you've been working a long time on yours, so it just must not make emotional sense to you, to see him react (or not react) this way.
But hopefully it really doesn't mean he's a "bad" person. Maybe if he sees that your emotion is loud and clear and kind of very visible about his mother's loss, he'll have a little more difficulty finding his own?
love to you, from your fellow orphan (and we're okay)--
Hops