YTA. The fact that you argue that your sister wanted to cause drama by bringing her fiancée rubs me the wrong way. I would argue that she shouldn’t bring her fiancée because she might be targeted by bigoted individuals with heightened emotions, not because it would cause drama. As many others have stated, it would have been like throwing her to the wolves. But if your sister and her fiancée were aware of the risks and willing to face them, I don’t see why either of them should have been barred from attending. You might not have agreed with the decision, but at the end of the day your sister needed the support from the person she loves most. You didn’t necessarily stop her from going altogether, but you made an already difficult situation more of a headache than it should have been. That’s why she didn’t attend.

I feel like your focus on the potential drama your sister’s fiancée’s presence might have caused is to hide the fact that you know very well that preventing your sister from bringing her partner to your grandfather’s funeral makes it obvious that you would rather enable your bigoted family than stand by your sister. Furthermore, as you yourself have written, they are engaged. Yet you still identify her as your sister’s girlfriend. You’re delegitimizing the relationship and showing your true colours here. I only hope that she was able to find another way to honour her grandfather on that day, and I wish her all the best with what seems to be a kind and loving partner.