I have 4 older stepsisters (2 at each house growing up), all of whom I've referred to as sisters, since our parents married when I was very young. One sister always made sure to correct me that she is my STEPsister. However, I was still planning to have her in my wedding party with the rest. To my dismay, when I showed this sister my ring to show her I had gotten engaged, she merely shrugged. Later that night, she told my mom (her stepmom) that she had been excited for her older sister when she had gotten engaged because they are "real sisters," but wasn't excited for me because I'm only her "stepsister." I decided at that point that she was NOT going to be in my wedding party if she is not even happy for me. Her older sister is upset with me, but I do not want to budge on this. Am I in the wrong?? Advice and input please!