The problem is, when I do that, I am the bad guy and my parents shut me out. That is the part that saddens me the most. When I do say "nope, sorry, it's my wedding and I don't want the Hummer limo, I think it's excessive," then no one will speak to me. It will eventually ruin my family and that's what makes me sad.
I'll have a big creme brulee though and that will make me just as happy!
It drives me nuts that they treat things this way, but what really upsets me is we are expected to treat her this way too. For instance when I said no, I really want the other bridesmaid dress I was pulled aside and got a talking to from my mom about how I should really go along with my sister, that she rarely feels pretty and she feels pretty in that dress. A good sister would let her get that one. And when I refuse to give in I am the bad person. I am the one they stop talking to. I am the one that gets yelled at for not giving in to her. I am the one that gets yelled at for causing my sister to throw a tantrum when I could have just given in and made things easier.
Well, then perhaps you have to distance yourself somewhat from your parenst as well. They are an integral part of your whole problem.
The way I see it you have some choices:
1. Resign yourself to the fact that this is how it is and if you want to maintain a relationship with your parents, then you will have to put up with your crazy sister. You can look forward to the fact that someday when your parents are gone, you will be able to write your sister off and never see her again. Nothing lasts forever.
2. Decide that the frustration and aggravation your crazy sister/parent relationship dynamic causes you is more than you can handle and so you are willing to forego a close relationship with your parents because they defend her. Then you can say to all of them "This doesn't work for me", and go on to live your life without them in it, unless they choose to meet you on your terms and not your sister's.
What you are NOT going to do is change the dynamic. Your mother is correct in saying that sister is 25 and it's not going to change. Your sister is mentally ill. Your parents have enabled it instead of getting her the help she needed when she was younger. In essence, this is their "fault", insofar as they missed the boat with regard to admitting that one of their children was mentally ill and therefore missed their opportunity to help her. You may not think they realize this, but believe me, they do. Their "acceptance" of her is their way to try and rationalize their mistake of not getting her help...if she is kept reasonably normal as long as she gets her way, then they couldn't have been that bad, could they have?????? The fact is, they screwed up royally with her, and they know it.
My DH has a crazy sister, with much the same dynamic. His mother, moreso than his father, enabled the bad behavior. Her constant refrain was "Just do what she wants to keep the peace". In an effort to not distress my late DMIL, that is what the siblings and their spouses did. It was a concious choice everyone made knowing that the consequences were dealing with the nut. Then both in-laws passed away within 9 months of each other. Crazy SIL got a little tough love, by being told point blank that the party was over, Mama wasn't here to protect her anymore, she would reap the consequences of her bad behavior and that we would all write her off as if she never existed if her behavior continued to be offensive. There were a couple of growing pains, there were a couple of times when I had to ask her "is it time for me to do the write off?" but she got the idea. She now behaves reasonably well, we are able to maintain a cordial relationship. She knows if she crosses us, she's done. However, I know full well that getting her under control would not have been possible had my DMIL still been alive enabling and protecting her.
Unfortunately OP, you are in the same boat. Your sister's behavior will continue until your parents are gone. Right now, good or bad, right or worng, fair or unfair, they are on her side & you are not going to change it, so accept it or distance yourself from all of them.
It is a difficult position to be in and I feel for you....
