My dbro was very close to me and my exh. We often did things together
When he got a serious girlfriend I knew that dynamic would probably change. Yes it made me a little sad but I was happy he was happy. We didnt do stuff together as much anymore.
They moved in and for a while she did come to things. Then around the time they got engaged she changed. I think she had decided she didnt like everyone being so close, fair enough, and decided to change it then. Bit she became very combative. If I text my brother asking if he wanting to do something or go somewhere, she would text and ask why I hadnt spoken to her as they decides these things as a couple. I told her, I thought texting one of them was fine and I wasnt going to assume she had to take on the mental task of organising everything.
If we had family meals, it had to be what she ate. She has gone vegetarian, gluten free, vegan and back again several times. They then had kids and she was a sahm,I was a working mum and she constantly tried to goad me into a sahm v wohm debate. I refused to engage because I genuinely dont care what other people choose to do. There not right way. I used to just say 'there no debate really. Everyone does what they feel is best' and removed myself.
I did the minimum. The final straw was when I went away with my mum and 3 other female relatives. Just was invited and said no. I posted some bits on social media while i was away. My dad was having g a day out with exh and the kids. Dbro called dad raging that she had been left out, we thought she was shit, pushed her out etc. Dad wasnt aware that she had been invited and felt awful.
LDbro threatened to ring mum (its was her birthday) and have a go. Dad begged him not to. Exh called me and told me what had been going on. He had heard both if then shouting at dad, including calling me some choice words, like bully and jealous of her.
So I sent them both a clear text, with a screen shot of the text asking her if she wanted to come and her response. I calmly explained that actually, I had asked and she had said no. Besides which she used to go away with her own mum and relatives and never ask mum to join them. So I was unsure why she would expect to attend everything others have organised, but that I did ask her anyway. That having a go at dad was not on and suggesting they call and apologise.
I didnt want her to come away with us. But I knew she was trying to create a wedge and blame me. This situation showed exactly what she had done I suspect she didnt tell dbro she had been invited then expected him to kick off about it. By sending the screen shot i took the wind out of her sails. I havent actually spoken to her since and only speak to my dbro occassionally. I am no longer expected, bu any family member to engage with her at all.
Long story short. My advice would be to not engage in her arsey behaviour. Invite her to the wedding. By not doing she can lay the blame at your feet. She wont create a scene because then she cant blame you. I would treat her as you would if bil had a serious girlfriend that you just didnt know that well.
You would seat her, if that was the situation, with him, surely? Unless he is on the top table?