@The Spectre I have tried. I have tried repeatedly and it ends one of two ways.
Either they repeatedly defend one another and essentially gang up on me, or they go into how much I hurt them by implying in the first place that they would ever do that. (In turn just shutting me up and apologizing for hurting their feelings and I just end up sitting there feeling stupid and/or guilty)
It never ends in a way that involves actually considering why I might feel this way or if they actually might be wrong or acting hurtful.
They aren't awful people at all. I adore them both. But they have their faults and this is one of them.
I don't doubt they care about me (shit one of them helped me with a very personal and disgusting health issue that I couldn't handle alone) but when it comes to each other they can be very blind to the tiny faults. (Such as forgetting to do this or that) They aren't blind to mine.