Aita For Confronting My Best Friend's Wife

AITA for confronting my best friend's wife after I found out she was secretly cheating on him with my own brother? I never thought I would be caught in something so explosive but here I am, trying to make sense of what happened. It all started when my best friend Daniel and his wife Lisa moved into the neighborhood. We instantly clicked, and I considered Lisa a close friend. She was charming, funny, and seemed genuinely caring. My brother Mark and I had always been tight, sharing everything. Things took a strange turn when Lisa started acting distant around me. She would avoid eye contact and cancel plans last minute. I brushed it off as stress from work until I noticed her phone lighting up with messages late at night. I should have ignored it but curiosity got the best of me. One night I secretly checked her messages and could not believe what I saw. There were messages from Mark. Not just casual chats but intimate conversations, plans to meet secretly, and flirtatious remarks. I felt a punch to the stomach. My mind raced. How could she betray Daniel and me like this? I felt betrayed and furious. I decided I had to confront her. The next day I invited Lisa over for coffee. I pretended to be friendly, but inside I was boiling with anger. I told her I knew about the messages and asked her what was going on. Her face went pale, and she stammered. Then she broke down and admitted she had been having an affair with Mark for the past six months. I could not believe what I was hearing. I felt like my world was collapsing. I told her she was a terrible person and that I could not trust her anymore. I called her a liar and a cheat and told her to leave my house. I then confronted Mark. I asked him how he could do this to his brother and to his best friend. He tried to deny it at first but eventually admitted everything. He said he was sorry but could not resist her. I felt disgusted. I wanted to tell Daniel but I was also worried about breaking him completely. I decided I could no longer keep this secret. I told Daniel everything. He was shattered. He cried for days and said he felt so betrayed. I wondered if I did the right thing by telling him or if I should have kept quiet. Now Daniel has cut both Lisa and Mark out of his life. I lost two friends and a brother over this mess. I keep asking myself if I am the villain for exposing the truth or the hero for saving Daniel from further pain. What do you think I should have done?