My fiance's step-sister and I have known each other since we were five years old and have pretty much been best friends ever since. She is my maid of honor and she couldn't be more excited. I was going to ask my fiance's twin sister to be a bridesmaid, but he wanted her on his side so she is going to be one of two groomswomen in our wedding and his brother is best man. My future mother-in-law doesn't agree with this decision at all. She seems to think his sister should be my maid of honor rather than his step-sister even though her and I are best friends. My fiance is the one that decided to make his sister a groomswoman, but he also knew she was never going to be my maid of honor because it was between his step-sister/my best friend and my sister. However, because of his mom's comments he seems to be second guessing the bridal party. He hasn't come out and said that his sister really should be my maid of honor, but I can tell his mom's opinion is really weighing heavily on his mind. I'm not sure how to handle this because there is tension now between my fiance, his mom and I. His sister is so laid back that it doesn't phase her at all that she isn't my maid of honor or his best woman.