I'm getting married in a few months, all being well with covid. Maid of honour has mentioned today that her partner is coming even though he hadn't been invited. We really don't want him there as he is abusive towards her and she wouldn't be able to relax and enjoy herself with him there. We did try telling her that a place/meal hasn't been booked for him and she's said it's fine but she needs him there to help with her DS. He's never attended previous family gatherings, and actively dislikes my wife to be! How do we tell her politely that we don't want him there! We need to be diplomatic as it's a very long standing friendship and it's us she turns to when he gets too much.