Just who was in the wrong here? (family meet up)

Yesterday I went around to my older sister's for tea, basically we all went over including my mum and dad for tea and biscuits and to watch the FA cup. My sister and her partner were there with their 2 kids, when I arrived my sister and her partner said hello, that was it (not how's it going, how's work like normal people, just hello), her kids basically ignored me and I sat in the living room waiting for my mum and dad. They arrived a while later and we had tea and biscuits and we all sat in the living room with them spending about an hour talking amongst themselves. Every time I said anything I got ignored and my sister changed the subject. So basically before the match started, I got up and left and went home without saying goodbye. My mum then texted me saying I had been really rude. I texted her and told her that they had all been rude to me, as they had just ignored me. Who was wrong here? My sister and her family never show any interest in me and whenever I say anything they just ignore me, so basically I just left.