My gf (F30) and I (M33) are having an argument over a situation involving her sister (F26). Her sister is being harassed by an older person (M58 or somewhat), who is a typical fat and ugly guy (for context, to you know this is definitely not the choice of the sister). This goes back 4 years, and it still hasn't stopped. It even went to court. The court ruled that the older man was not guilty of stalking, but there was enough evidence that he was harassing her. A lot has happened since. and even the family of the older was involved at some point in the early stage of the situation.

At first, they attacked the sister for being provocative towards the man. The man made claims that she took initiative, etc. But luckily, the sister had already built her case and showed them the evidence. The older man confessed to the family that he had harassed her. The family did nothing after that and said they supported the sister, but did not actively try to stop the older man. That was infuriating to the sister and her family. My gf and sister demanded that everyone engaging with the family of the older men didn't take their side and even demanded that people shouldn't invite anyone from the family of the older man to a birthday party or whatever. They gave them an ultimatum: if a family member is coming, we are not coming; they should feel what we feel. Hopefully, they say, I they are hurt, they will stop the older man due to the social pressure (which for me sounds a bit extreme already). But they believe the family is the only one that can stop the older guy, because different official agencies didn't scare the guy or couldn't stop him (because of the lack of committed crimes).

Now to the argument, my father is hosting a public event (1/3 of the hosting members) in our village on private terrain (of my father's), and my gf is demanding that my father should deny access to the family of the older man. In my opinion, my father cannot deny them access, because it is a public event. But my gf says it is private terrain and says: if he doesn't deny them access, I am not coming, and my father is making the choice to not support my gf and her family, but does support the family of the older man. IATA for agreeing with my father and that the ultimatums are too extreme. Basically, my gf is projecting the pain of her sister and her family on others and wants people to feel the same pain. Or am I in the wrong?

There are many examples of putting people in situations just like my dads situation, and they are sort of shutting themselves off and are only engaging with people outside of the village. Because they do not have the relationships in the village, they can understand them better, and are fully agreeing with their actions.

(Hopefully the story is readable and clear, because it is a very complex situation and my English is not my first language...)