Found my husband texting my sister

TIFU by checking my husband phone on our anniversary and finding out my whole marriage was a lie. I am Rachel and I have been married to Mark for six years. We were celebrating our anniversary at home with wine and candles. He fell asleep early because he had a few drinks and I decided to charge his phone since it was dying. A message popped up on the screen from a contact saved as Work Gym Buddy. The message said I miss you already come back soon. Something about it felt wrong so I opened it. What I found made my stomach drop to the floor. There were months of messages between Mark and this person. They talked about meeting up at hotels and how they could not wait until they did not have to hide anymore. I scrolled further back and saw a name mentioned casually in one of the texts. The name was Jenny. My sister. My own sister Jenny who I had dinner with just last week. My hands were shaking so hard I almost dropped the phone. I kept scrolling hoping it was some kind of coincidence, another Jenny maybe a coworker. Then I saw a photo. It was Jenny in our bed, the same blanket I had picked out for our wedding registry. I felt like I was going to be sick. I sat there for almost an hour just staring at the screen, replaying every family dinner, every holiday where Jenny sat across from me laughing and hugging me like nothing was wrong. I thought about every time Mark said he was working late or going to the gym with his buddy. It was never a buddy. It was my sister. I did not wake him up that night. Instead I sent myself every screenshot as proof and planned my next move carefully. The next morning I made him breakfast like nothing happened. I needed him to feel safe before I confronted him in front of everyone. Two weeks later we had a family gathering for our mother birthday. Jenny was there smiling, hugging me like always. Mark stood beside me acting like the perfect husband. I waited until everyone had a plate of food and the room got quiet. I stood up and said I had an announcement. I said I wanted to thank my husband for being so romantic this year, especially with his gym buddy texts. The room went still. I pulled out my phone and read one of the messages out loud, the one where Jenny said she loved sneaking around because it made things exciting. Jenny face went pale. Mark nearly choked on his food. My mother dropped her fork. I looked straight at Jenny and asked her how long she had been sleeping with my husband. She tried to deny it until I showed the photo of her in my bed. The room erupted into chaos. My father started yelling at Mark. My mother started crying asking Jenny how she could do this. Mark tried grabbing my arm begging me to calm down and talk privately but I pulled away. I told him there was nothing left to talk about. I filed for divorce the very next day. Jenny tried calling me nonstop but I blocked her number. My parents sided with me completely and cut Jenny off from family gatherings. Mark lost his job a month later because apparently Jenny was also sleeping with his boss and that blew up too. Karma works fast sometimes. I am rebuilding my life now, slowly but surely, surrounded by people who actually care about me. Sometimes the people closest to you hide the darkest secrets. Would you have confronted them privately or publicly like I did.