I’m all for exercising your no muscles. Say what you mean and mean what you say. However is who your sister is marrying worth breaking your relationship over? Only you can decide.
Here’s the issue. You may have genuine reason as to why you think your sister is marrying Mr. Wrong. You may be spot on. The issue is this you must voice how you feel and then let it go. If you are truly in a place where you feel an enormous amount of guilt then you have to really be true to yourself.
However it may come down to simple terms. Yes you feel strongly about her fiance but that’s still your sister. You have to be able to separate the two and still let her know you love and support her the person. You and her being related doesn’t automatically mean that once you speak up that family has to do what you say.
There are some journeys people have to walk along and marriage is one. If he’s abusing her then by all means again you’re in every right to feel upset. Be sure that you’re ready for the fall out over declining her maid of honor request. Tell her why and early don’t lead her along by acting as if you accept.
If abuse isn’t the issue or any negative treatment is going on search your heart. Maybe it’s not jealousy or envy. It could be that you just indirectly want things to be the way they were. That’s not your sister’s fault that you don’t like change. You I’m sure wouldn’t want to delay your life should someone propose to you why should she?
Sisters are nature’s first set of friends. Often times the disagreements and fights are there to help you mature. Don’t treat your sister less than you would a friend. Be courteous and be there for your sister. If the marriage isn’t meant to be it will reveal itself to your sister when she receives the lesson for her.