My partner hasn't spoken to his dad for nearly 12 months due to a falling out they had. In this time I kept in touch with partners dads wife and helped her keep her relationship with our 1 year old daughter. After 5 months she blocked me on all social media no explanation noting. Our daughter has seizures and spends a lot of time in hospital. During these 12 months not once have they visited sent her a birthday card or even asked how she was. On Christmas day partners dad posted a card. Addressed only to my partner wishing him a merry Christmas and saying how much they missed our daughter. My name wasn't even mentioned. My partner decided to get in touch and met his dad. After sorting things out they agreed to meet up again in the future with our daughter. I wasn't even mentioned. AIBU to be upset. Their falling out had nothing to do with me so why is acting like I'm irrelevant in his sons life.