Here’s another thought ~ Could FIL be (even subconsciously) angry that DH (as a teenager/young adult) didn’t help out more when MIL’s MS got to be an issue?

I wish I had words of wisdom, but without confronting it directly (or even by family and friends asking “FIL (Phil? LOL) what’s going on here?”), you are resigning yourself to this dynamic ~ with no answers.

Don’t know your belief system but:

Prayer work?

Mantras? (Can anyone reading this suggest a good one?)

I’ve had something like this (Who am I kidding, I HAVE this!). The family lawyer (who has known 4 generations of the fam!) was so puzzled by my Dad’s non-involvement that I think he ambushed us! We both found ourselves over to his house for dinner. Lawyer and his wife were looking at me and Dad’s interactions like we were exotic jaguars who had never met before. “So much alike! Yet so much not alike!” At the end it’s just one of those mysteries that you just have to write off with a shoulder shrug.