As STBX, who knows what was behind the behavior, but given MLC, it is probably as simple as plain old selfishness. I'm so sorry, it is almost impossible for us (relatively) normal folks to grasp how they could behave so very deceptively. But they do.
One day at a time, rely on your L, and treat this as a business transaction. Hard to do, I know all too well. But that's all the decent advice I have!
