Come on, you just lost two people who were already betraying you behind your back. They weren’t your support system. They were your liabilities, and the only reason you’re shocked is that you believed their performance instead of watching their behavior.
Your “best friend” wasn’t just disloyal. She was deliberately, repeatedly, shamelessly sleeping with your boyfriend while planning a wedding and asking you to stand at the altar as a bridesmaid, like some twisted joke she was in on and you weren’t. That level of deceit isn’t a mistake. It’s who she is. And you’re still debating whether to protect her, confront her gently, or keep her fiancé in the dark. Why? Out of loyalty? She incinerated that.
You don’t owe her silence. You don’t owe her protection. You don’t owe her a soft landing. She made the mess. She gets to live with the consequences.
As for her fiancé? He’s about to marry a woman who has been cheating with her own best friend’s boyfriend. If you stay quiet, you’re helping her destroy someone else’s life the same way she destroyed yours. That makes you complicit. Brutal, but true.