OP laments that while her sister didn't actively pick on or bully her during their high school years; she would stand by with her head down while other teens, who were her friends, ridiculed her twin.
As an example, OP tells of a time when they were getting ready to celebrate their 16th birthday. OP didn't have any friends and didn't want to attend the party, but knew her parents would expect her to be present.
At this point, OP is adamant that she doesn't want her sister to be in her wedding, but her parents think it's a good ‘compromise' to have her twin be a ‘regular bridesmaid.'