I've been with my partner just over a year but have known him and his family since we were children. When we got together, I was seeing lots of his mum, sister, brother and brothers girlfriend. Had them over to dinner, hosted family parties, babysat their children etc. Last July, I noticed a shift in atmosphere around partners sister, brother and his girlfriend and asked partners mum if she'd noticed anything, or if I had unknowlingly upset someone. She said she wasn't aware of anything and thought I was being overly sensitive. Over the next few weeks, contact with all three of them completely stopped (had been very regular before that) and partners brother and his girlfriend unfriended me on social media. Partners sister had invited myself and my children to stay with her in the summer and when I messaged to ask about dates, she simply never replied. Partner said he had no idea why, partners mother said the same. I told partners mother that I intended to ask them what the issue was and she asked me not to as she was concerned it may "cause trouble". I did as I was asked and hoped some sort of explanation would come about. It never has and I am now excluded from everything which involves them. Partner still goes to visit them etc. with his children. Myself and my children are excluded from these visits. At Christmas, I bought gifts for all their children (6 of them) from my partner, myself and our children. They bought gifts for my partner and his children but nothing for me and my children and none of them ever thanked me for the gifts. I explained to my partner how hurt I was and he again told me he had no idea why they had suddenly cut me out. It has upset me but what has upset me more is that my partner has never asked them what the problem is or in any way brought the situation up with them. This all came to a head a few days ago when partners sister was visiting his brother (who lives 10 minutes from us) and partner went to their house to see her. When he came back, I told him again that I was upset he didn't seem to have any loyalty to me and whilst I didn't want to cause trouble in his family, I really think he should have asked them all why they have chosen to exclude me and my children in this way. He says its none of his business. I feel really strongly about this and think he should have at least asked them what is going on. So, am I being unreasonable to expect him to have my back? Sorry for the long post.