Me (M20) and my cousin (F21) have always been close. We've had our fights, but we've always made up. We were progressively fighting less and less and communicating a lot better, but this summer she did something unforgivable.
She pressured me to go on vacation with her to a place where some people I hate live, because she promised me we would spend time together. What actually happened was she also brought 2 friends (F17 and F22) along and she constantly ignored me so that they could flirt with some guys and only spent time with me whenever they weren't around. At first, I showed some understanding, but I eventually had a serious conversation with her and she promised to tell me to come along next time.
I don't know why she changed her mind. It might have been her own decision or her friends might have told her they didn't want me to come. They used the fact that I had hung out for a few minutes outside with a friend whose brother turned out positive for covid to tell me that I should stay home because my cousin's father-in-law has cancer. I had a test, had no symptoms, was fully vaccinated, and even offered to wear a mask while in the car with them, but they constantly said "you never know". I then asked them why they were planning to chill with the other guys who didn't do a test, thus making them more "dangerous" to be around, if they want to be extra careful. They said that "just because covid exists that doesn't mean we should shut ourselves in" and that it was fine because "they won't be indoors". I later found out that they gave another girl a ride without an issue and when I called my cousin about it she hung up on me. Her friend then texted me "does it matter if we did? I think this conversation should end!"
That was the last straw and I bought tickets to leave that place the very next day. I didn't even say goodbye to them and when a friend (M20) told them I had left he told me that they were "shocked and didn't understand why I wanted to leave".