Sometimes the “why” of shitty behaviors doesn’t matter all that much when you’re trying to set boundaries.
I’m positive that the ex-boyfriend from 10-12 years ago who hit on my friends behind my back and told me it was my fault for being unattractive when he got caught (I have good friends) was suffering from some sort of depressive thing. He was also a dick who was behaving like a dick to me. Does knowing he had a mood disorder and having compassion for why he must have been feeling so insecure that he had to “act out” actually help me with anything? No. You know what helped? Telling him to fuck off and never talk to me again.
We spend a lot of time trying to get to the bottom of why people are being shitty as if we can somehow fix those emotions if only we knew why they were happening. The LW’s sister is being SUPER-shitty. I’m almost certain that she is deeply unhappy and could benefit from talking to some kind of medical pro. But say the sister never visits a doc, never gets a diagnosis or treatment of any kind. The LW will still need her to stop treating her like crap, yes?
Sometimes the answer is “Stop treating me like crap. Your sadness is not my fault, and you don’t get to use it as the reason you treat me like crap.“"
Captain Awkward (does it again.)
This is also so, so relevant right now.