My sister has had a friend, long term and I would call her a family friend for many years (she was in fact the younger sister of my sisters actual friend). Anyhow, this particular person, lets call her Pamela has come to lots of family events, we have children the same age etc.
My sister has actively encouraged me to treat Pamela like a joint friend, told Pamela to call me when she had some issue with her daughter during teenage years (my daughter a year older, been there, done that) also when Pamela fell on hard times and couldn't afford Christmas Lunch etc, my sister was on holiday abroad and I stepped in invited her for Christmas and boxing day, so she and her daughter & son stayed two nights and we looked after and made sure they had a good Christmas. Sister was fine with this, I welcomed her into our home etc etc. This was a few years ago, but we have always kept in touch, if each other have a social event, then the other is invited. She has often called on my for a listening ear (and vice versa) over concerns/worries about our respective children.
Over this Christmas, she met a new partner (YAY!!!) she had been through a dreadful divorce with an abusive ex. Again my sister was away and Pamela was totally stressed about her new man, worried he would change his mind, worried she was getting too serious, she text me a lot. Long story short, they are still together and blissfully happy! No one deserves that more than Pamela. We got quite close over this time, although we were always friends and got on well.
Now Pamela is a very good organiser, lot's of things she organises are not my cup of tea, that's fine I don't go.
My sister for some reason thinks that her relationship with Pamela has "cooled" and the Pamela is excluding her. I don't think she is, but I am not her so I suppose I don't know. Pamela tends to create FB invites for everyone and sister is always on them of course.
There was an event this weekend that I fancied, sister was away so could not go. I went, now sister is obviously not happy with this, she has not asked how my weekend was, how it went etc. I have seen Pamela on my own before so this is not a new thing (not lot's of times, but she cooked dinner for me one night when she was back on her feet etc). I have not been on an event with Pamela on my own for years before this, but I have done it.
Basically, I feel that sister is saying, she is my friend and I don't want you seeing her before. Even though she wanted me to have her to Christmas and in fact was asking me to have her again the following year, but this was not possible for me. She now is more or less saying I think you should drop her as I feel excluded (which she is not!!).
AIBU or is my sister BU?