I (35F) was in a relationship with a man, let’s call him C (50M). C is a wildlife photographer, very outdoorsy and adventurous guy. He has a decent social media presence and portrays himself as soulful, genuine and trustworthy man. The first six months of our relationship were blissful. He was very thoughtful, communicative, supportive and loving. But then, the dynamic started to shift He became irritable and easily angered (which was a jolt as he’s typically a very mellow guy). We were arguing more, we’d have breaks but then get back together. This lasted throughout the summer. I knew it was toxic but I continued to make excuses for him, and I have a lot of guilt about that. Anyway, fast forward to almost a year together. I am flying home from a bachelorette weekend. As my plane is taxiing, I receive a Facebook message from a woman, let’s call her A (40F). Her face was familiar as I had seen my bf post a beach photo of the two of them on his Strava account. Yes, it was weird he did that, but I figured it was just one of his instagram fans. When A messaged me out of the blue, it was off from the start. First, her facebook profile pic is a happy one of her, her husband and child. She starts out by asking me if I know C. I said ‘yes?’ She asked how. I told her we were in a relationship. She asked me to prove it, she asked what pet names he called me (C is big on the pet names). I told her - ‘he calls me muffin, lover, amongst others’. She said ‘you’ve been cheated on.’ I was confused, with her? She said ‘no I’m not saying it was with me.’ But as we talked further, it became pretty clear it was with her. She even sent a screenshot she sent to him about her ending it. At the same time, I am messaging C telling him I know what’s he’s done He shifts the blame on me, calling me vindictive and vengeful, and then ghosts me. I’ve never heard from him since. So, I’m initially very grateful to A for sharing this. The next day, I message her saying I respect her privacy and am grateful for her message. She responds she’s grateful to me as well. So a week goes by, and my brain is in circles over this as I’ve had no closure from C, and so I reached out to A again asking if she could clarify the timeline. Her tune changes, saying ‘oh well it wasn’t me, it was my friend, I’ll have to ask her when it stated.’ I was confused but played along, maybe she’s concerned her husband will read the messages? But then A asks ‘are you still seeing C?’ I don’t respond and she asks again ‘Are you still seeing him???’ I said no, and hoped that “her friend” wasn’t either given he had been exposed as an old lying cheater. She replied ‘yes, it seems very heavy and complicated.’ Over the next few weeks, there were additional exchanges. It became clear that they were still together, and she was still with her husband. I am an introverted person and only share my personal life with a few close people who I deeply trust. They all had my back, reaffirming to me how horrible C is and how it was obvious that A was now trying to convince me into believing it wasn’t her, when it clearly was. A common theme we discussed was how bad we felt for A’s husband. While it’s possible the situation was ENM, that’s really uncommon in our area. I mean how horrible would it be to be the last one to know your wife is cheating on you with this guy? So, i eventually agreed to send my friend the beach photo of them to be posted on a local ‘cheaters exposed’ facebook page. Their names and locations weren’t used, just initials. Since C has a social media following, it didn’t like long (ie less than an hour) for it to gain traction and get back to him and A. I am now the ‘crazy ex.’ So, AITA for outing them?