I might be in the minority here but I believe that the option should belong to your brother and your sister. Now your sister has obviously made her choice she does not want W there. Your brother is backing you up but it is not just about your brother it is also his bride to be day. I am thinking you are missing the big picture here.
You say you will be miserable with W there? Well guess what buddy, so will she. This is a constant reminder of your failed M? What do you think it will be reminding her? As we have said time and time again it is the same for these WAW, they all feel the same way they all say the same thing so you know what is happening with her emotions. You are surrounded by family and friends and if she shows up she is one brave soul. This day should probably very uncomfortable for her.
Second reason why I disagree with not inviting her. This is a golden chance for you to DB you a$$ off. Think about the opportunity here for a moment. You have lots of support, she is going into the "lions den" this is a chance for you to be shown in the best possible light.
Third reason. Don't draw a line in the sand man. You've come too far by doing this you will demonstrate to her and yourself that your changes were about getting her back and not about you. This could come back and bite you in the a$$.
