My Dad passed away suddenly, less than 5 years ago (can't be anymore specific than than incase someone realises it's me!). Mum has been dating the same man for about a year. I'm in my mid-twenties and my sister is still in her mid-teens. She has not taken the relationship well at all, but I have been supportive although inside I've had reservations and it's hurt a bit to see my Mum with someone else.
I asked her a few months ago if she would ever marry him and she said no, but if she did it would be none of my business. We're normally a very tight-knit family, so this hurt me. I asked her to tell me the truth, but she still insisted she had no intention of marrying him. I told her that though I fully support her relationship, I couldn't handle the thought of her marrying him. I don't know why, I can't put it into certain words, but it would hurt so badly. Both me and my sister miss my Dad so much and it's still very much a raw subject for us. Mum is so different with this guy.
He's recently bought her a diamond ring which she initially wore on her engagement finger. She just came round one day wearing it like it was nothing - no prior conversation, and didn't bring it up until I pointed it out. I got quite upset, and eventually she started wearing it on her middle finger, saying that it wasn't an engagement ring. I told her I didn't think I could go to a wedding, if she had one and that I was worried our relationship was fraying a little. She said that if I felt that way, it was my choice and she can't live her life to make us happy. I've seen pictures of her wearing it on her engagement finger at his family's functions and I just feel so, so upset and lied to as I feel like she's telling me and my sister one thing and saying something different to everyone else. My younger sister is devastated and I just feel like my family as I knew it is falling apart. My DH is wonderful, but there's only so much support people can give when the actual problem isn't getting resolved.
I don't think I could go to this wedding, if it happens (which it blatantly will). I've never been selfish like this before, I've been supporting Mum in every way possible since Dad died, and I want her to be happy, but the thought of her marrying this guy is breaking my heart. I feel like the Mum I knew is gone. Mum has always been so wonderful but this is just so upsetting. It feels like the repercussions of Dad dying didn't stop at his death iyswim.
Am I being unreasonable? I just don't know anymore. Thank you.