I was not planning on having my cousin in my wedding. I did not even think it would even be a possibility until she was "engaged" for about a week and asked me to be in her wedding... Well when I saw her for lunch she said she would be really upset if she wasn't in my wedding AND "make sure I am in the front because I was in a wedding before and was towards the back and it made me mad, so make sure I am in the front"... We are not friends but we are family that sees each other often and she has a terrible attitude and is not someone that I want my future grandparents to be around. I realize she will be there and around them I just don't want that image to be portrayed to my future in-laws and friends.
What do I do and say?