My fiance and I have been together for 3 years. He’s very close with his little sister who’s planning to get married in 2025. A few months ago, his sister asked her brother (my fiance’) to stand up with her as a Bridesman on her wedding day: I was very excited for him, as I know his sister means a lot to him. A few weeks ago, I went on her wedding website and noticed my fiancés ex girlfriend is also standing up in her wedding. His ex and him dated back in high school and is now married to someone else. However, I feel completely blindsided and uncomfortable about the entire situation. I feel as your future SIL, a conversation should’ve occurred with some sort of warning. I would’ve sucked up how uncomfortable the day is going to be knowing my fiance will be spending the day with his ex celebrating with the other people in the bridal party. Do I have a conversation with my fiancé’s sister letting her know how uncomfortable this situation is for me?