Right, I've been warring with this for a while so I'm gonna throw it out there.
I've not been particularly close to my brother and I can't stand his girlfriend. I don't usually take such a strong stance on people but hopefully the rest of the post will fill you in on my reasons. They have been together two years.
She is currently pregnant with their second child together and she already had two children from previous relationships aged 9 and 11. I like her kids but don't see them very often.
They have an awful relationship and are both as bad as each other (my opinion but based on the following). They are very on/off and he moves back to my mums at least once a month (my mum is aware that she shouldn't let him do this but is also worried about what one of them will do if they stay in the same house as they have AWFUL arguments. She also feels it's not fair on the kids which is valid). When they have broken up she has been incredibly rude to my mum who had helped them out a lot financially. My mum is not a meddler (again I know I might see her differently but in general terms she is one if the most laid back people I know) and has been very good about saying nothing negative about her until very recently. She has also asked my mum to babysit on occasion then cancelled at the last minute (my mum really looks forward to these as she doesn't get to see the baby very often). My mum has been really good with the other kids, picking them up from school and babysitting etc. She always gets presents for all the kids rather than just the baby etc, as do I. We've very much tried to welcome them to the family when she allows us to. She doesn't let my mum or my brother see the baby when they are 'separated' which I think is the main reason he keeps going back. We've told him to fight for access and I've said he's a fool for getting her pregnant again (perhaps too meddly but I'm starting to get upset on my mum's behalf more than anything).
Last christmas my mum invited us all over on Christmas Eve. She was working on Christmas Day so this was going to be her Christmas. On the morning by brother and his girlfriend had a row and she text my mum telling her she wouldn't be coming. She refused to let him bring any if the children and they had been really looking forward to it. This concerns me with regards to them turning up for the wedding.
On a more personal (and probably quite snobby?) note she doesn't work and never has. She's just turned 30.
Part of me thinks invite them all and if they don't turn up they don't turn up. The problem with that it if they don't come that's 5 or 6 spaces that a) I've paid for and b) someone else could've had. I can only have a maximum of 75 people at the ceremony including the registrar, TOG etc and babies are included in that too. We are already having to exclude people we really want there and I'm reluctant to cut out close friends for the slight possibility of her turning up.
The reaction I've had from the people I've told so far is 'really, you're not inviting your own brother's girlfriend?'. It makes me feel like I'm an unreasonable cow. Maybe I am? Some objectivity please.
My OH isn't a fan if either of them but understands he is my brother. We'd recently agreed that we would invite them and see what happens but then they broke up and my brother has now been back at my mum's for two weeks. I've spoken to him about all if this and also said I would love for his don to be a page boy but I'm worried he won't be allowed to come. He agreed that this would probably be the case and got quite upset.
They may well be together again next week, they may not. Aargh, what to do?! Invites go out after Christmas. Sorry to ramble!