I met most of my boyfriend’s family, but never met his older sister (she’s 29). We were over at his mom’s house for a Super Bowl watch party. He introduced me to his nephew (her son) and she was a little standoffish and looked away. His parents and relatives always make me feel welcomed, but she never really acknowledged me the entire 3 hours I was there. I was looking in the mirror waiting for someone to come out of the separated bathroom. His sister comes out and I’m still in the mirror, but she never looks up. She gets something off of the counter and says, “Excuse me,” then goes back into the bathroom for something. They have a very close relationship, but considering we’ve never spoken or met before, I thought she would be more like the rest of the family. They always have smiles on their faces and are very genuine and complimentary. I can’t really say she was having a bad day because she looked like she was enjoying herself and laughing a lot. Unfortunately, that is not what I expected. Thoughts?