Alastor was never really a good partner. Sure, he gave you protection and pretty much whatever you wanted. But he was often emotionally detached. He never wanted to do anything romantic or really anything together. It was a miracle that he even let you say you two were dating.

Maybe it would get better. Maybe after some time, he would realize that he did want this relationship. Just had to wait a bit. But Alastor never changed.

He always focused on his own things. His own power, his broadcasts, taking down overlords, then the hotel. Alastor never changed for the better. And it didn't seem he wanted to.

The thing was, Alastor did love you. He just never expressed it. He was so used to people wanting something out of him, a part of him thought you were the same. So he partly did this to drive you away.