My fiancé's family is a bit troubled. His parents had a messy divorce a few years ago, and his father recently remarried. His new wife is a very nice woman, but because of the unpleasant relations between everyone (his dad is kind of on the outs for many reasons), my fiancé and his family really do not like her (and no, his dad did not cheat on his mom with this woman - or any other, to my knowledge). I told my fiancé that we could handle the situation however he would like to concerning the guest list for the wedding, since this issue is far more sensitive for him and his family than it is for me, and he has decided to invite his stepmother but not her children. We have not told her or his dad this yet (and I'm not going to lie, I'm pretty nervous about how they're going to take this news), but it is his decision and since he is my fiancé, I'm going to stand by him on it.
My newest worry with this issue is the guest list for my bridal shower (which, it should be noted, isn't going to actually happen for several months - I tend to worry about things WAY in advance, haha). My sister (the maid-of-honor) is planning it, but I will be letting her know who to invite from his family and from my group of friends. Obviously, my fiancé's mother and sister will be invited... but I'm not sure if I should invite his stepmother and stepsister. He's not close with either of them and I've only met each of them a few times over the 4+ years that he and I have been together. At the same time, regardless of how everyone gets along, after June 20, 2014, she is going to be a part of my family, and honestly, she's a very lovely lady. She'll be a grandmother to my future children and I would like to get along with her. I think that inviting her to the bridal shower would be a good way to make her and her daughter feel included. At the same time, I do not want to make my fiancé's mother and sister feel uncomfortable, and having his stepmom and stepsister there definitely will. I understand why there is so much animosity towards his dad and his wife, but since I wasn't dating my fiancé when his parents divorced, I do not have harsh feelings towards them like everyone else does. I'm in the incredibly awkward situation of offending my fiancé's mom and siblings or offending his dad and stepmom - I can't see a way to make this situation comfortable for everyone.
I could really use some help with this! Any advice would be greatly appreciated.