The Cousin Affair Aisle Bombshell

AITA for ruining my best friend's wedding because I found out she was cheating on her fiancé with her cousin? I never thought I would do something like this but I could not stay silent. It all started a few weeks ago when I overheard my best friend Lisa talking on the phone. She was whispering but I caught enough to understand she was planning to meet someone secretly. I was curious so I kept listening. It turned out she was cheating on her fiancé Mark with her cousin Jake. I was shocked. I trusted her completely. I never thought she would do something so reckless. I decided to confront her. I called her later that day and asked if the rumors were true. She denied everything at first but then broke down and admitted she had been seeing Jake for months. She said she loved Mark but she could not resist Jake. I told her she was making a huge mistake. I warned her that if she went through with the wedding, she would ruin lives. She begged me to stay out of it. I decided I could not let her marry Mark knowing she was cheating. I planned to tell him everything on the day of the wedding. I thought it would be the right thing to do. The wedding day arrived. Everything was set. Lisa looked stunning in her dress. Mark looked nervous but happy. As she was about to walk down the aisle, I could not hold it anymore. I took out my phone and played the recording I had made of her confessing to Jake. The room fell silent. Mark looked devastated. Lisa's face turned pale. She tried to run out but I blocked her. I told everyone the truth. The crowd was shocked. Lisa broke down crying. Mark looked betrayed. The wedding was called off immediately. I felt a mix of relief and guilt. I never wanted to ruin her happiness but I could not watch her destroy his. Later that night, Lisa messaged me saying I had ruined her life and that I was a terrible friend. I wonder if I did the right thing or if I was just a revenge seeker. Should I have stayed silent? Or was exposing her the only option? I am still unsure.