My uBPD mom and eDad would always favor one of my siblings over me or my other sibling. One year, favored sibling (who is also uBPD) refused to have anyone over for Thanksgiving, which was fine with us because no one actually expected her to. So my SO and I invited my parents to eat with us at a restaurant that would serve on Thanksgiving, though it was in a city that was 1.5 hours away (we all live in a very rural area; also favored sister only lived about 30 min from target city, which will be important in a second). My parents agreed but wanted to take separate vehicles, which was fine. We arrived in city with restaurant and called them to see how far away they still were because they weren’t there yet. Turns out, favored sister called them on their way, changed her mind, and invited them over last minute. So they went to her house instead and were already eating. We haven’t invited them for holidays ever since.