I have a really good friend who just got engaged, and I really think she is making a mistake. She hasn't been the same since they got together. She doesn't do anything she used to do, and he's really boring — she seems so bored and sad all the time. She always does whatever he wants. I want to tell her, but I think she'll hate me. Also, many years ago when I was just coming out of the closet, I admitted that she was my first crush. It upset her, and we weren't that close for a while. Now I think she'll think I just like her again, but I'm dating other women and just care about her as a friend.
Talk about being stuck between a rock and a hard place. You and your friend share a complicated past, but your present predicament is actually simple: You've gotta tell your buddy how you feel.
A sustainable friendship — or any relationship, for that matter — is based on truth. Without it, there's no trust; everything is superficial. Let's imagine what happens if you don't tell her: They get married, and — since you have to hide how you feel about her spouse — your friendship slowly dissolves as it grows harder and harder for you to be authentic around her.
You don't want that, right? So, let's say you do tell her. There's a chance she won't want anything to do with you, and you'll have lost a friend for good. Maybe she'll blame your objection to her marriage on your old crush — maybe not. But she will feel judged and vulnerable and could say any number of hurtful things.
You don't want that, either, but here's the thing: If she really is as miserable as you suspect, and the guy is ruining her life, she must know that on some level. Maybe she's not ready to admit it to herself. People make mistakes, and you can't force her to do or not do anything — no matter how much you care about her. But, just maybe, she'll be relieved that you spoke up. Maybe she really needs to hear this from a friend right now.
However you approach this situation could result in lousy consequences for you. But don't let that outcome get in the way of telling your friend that you care — that you want her to be happy. Tell her that you miss your old friend. Even the best friendships can have bumps along the way, but I hope you two can ride them out together.