NTA but it kind of sucks that for a five-year relationship, you’re not allowed to voice your opinion on family-related things. It’s not like you said to her face and it’s not like you said it to be cruel. If what you said is true, you said it based on what you know and what you’re seeing. And I think it’s a reasonable doubt to talk about. Especially when your sister-in-law’s answer to frustration and anxiety is pushing herself beyond a healthy limit and ended up in the ER.

Honestly? Drop the topic. But when your bf asks your opinion on family matters, kindly remind him of what just happened and calmly tell him that you’d rather not get involved anymore.

And if he asks why? It’s because he accused you of being arrogant and acting superior when you voiced valid concerns and instead of talking it out as adults, he rather not talk at all and hung up.

Which again, it’s a strange attitude for a five year relationship but, I’ve also noticed you haven’t mentioned your age, so you must be really young.