Posting in relationships to hopefully avoid being mauled on AIBU!
Just wanted to get some outside opinions on this. It's my sister's wedding in the summer and instead of a hen do, she's having a family day out, which is nice. What's bothering me is that she is inviting my ex along, saying that he's family and 'became family the minute I had my son'. I get on well with my ex so that's not really much of an issue except that I actually I have a new partner of a year who she hasn't invited.
I've said that my ex doesn't particularly expect an invite to the 'hen' do and that I'm not really happy with him being invited and not my partner, she just said 'he is part of the family'. AIBU to think this is quite weird? I don't expect her to necessarily invite my partner to the hen thing but inviting my ex and excluding him?
She also sent my ex a Christmas card and gave me one separately but not to my partner. 
For context, she and I have a somewhat fractious relationship, she's really lovely at times but often not very friendly or pleasant. She's asked me to be her maid of honour, which I've agreed to do but she has a really funny attitude and is quite rude when it comes to making arrangements etc. It's pissing me off.
Partner was not included on wedding invite either, and getting her to reply when I questioned that was like pulling teeth. She eventually said that both my ex and me can bring a plus one. Which is fine really but it's just the way she says things. I don't mind my ex being invited, he is a nice guy and if she's fond of him that's fair enough and it won't be awkward for anyone him being there. But the whole thing still seems a bit odd.
I know she's not that keen on my partner as she said she feels he puts on an act and is too huggy. I think this was just nerves though (he tends to get extra loud and chatty) and I told him about the hugging thing, he wasn't aware she dislikes this and doesn't hug her in greeting anymore. He's very even keeled and just lovely all round really so he hasn't teeth offence and has continued to make an effort e.g. at Christmas. Obviously she doesn't have to like him but he's done nothing wrong and it feels like she's being deliberately unfriendly and also quite disrespectful to me.
Anyway thanks for reading 
. What do you make of this?