How do I deal with the possibility that my close friend did something against my morals?

No one ever wants to think about their childhood friend, the person who saw you in your vulnerable and most tumultuous state especially during middle school turning out to be a sleaze bag (or was one). To be a bit clearer about my situation, I had a friend group in middle school, about 4 people, I'll use fake names to protect their identities. It was me, Rachel, Justin, and Peter. I met Peter before becoming close friends with Justin and Rachel, but Rachel was in elementary school with me and we ended up in the same middle school due to our neighborhood. I didn't really know Rachel in elementary school but just that she existed and was in another class. It wasn't until Peter started to date Rachel that I become proxy friends with her, and from there our relationship grew. Justin also was a mutual to Peter and we all sort of just started to hang out. Our middle school also had a high school so when it came to 8th grade we all were a bit sad since me and Justin would be leaving to other highschools meanwhile Rachel and Peter stayed at the same highschool since they were dating. Because middle school is such a strange time and puberty being a really big part of it, it was sort of implied that Rachel and Peter wouldn't stay together for much long (even though I thought otherwise since they were my close friends) but how I came about finding out was where it all started. I didn't really stay much in contact with Rachel, Peter, and Justin other than sending holiday and happy birthday texts during my freshman year in high school.

Until finally, Justin and I reconnected and met up with Rachel/Peter. I'm not sure who we met up with first but I remember finding out during my sophomore/junior year that they were not together anymore. Both Justin and I were shocked since we remembered them being madly in love (of course this was puppy love), so when we began to ask questions this is where it got messy and confusing. Peter said that Rachel cheated on him and broke his heart, and that she was confusing and distant towards the end of the relationship - that she seemed to have grown cold towards him. They had broken up publicly in high school and it was pretty bad since 90% of our middle school stayed in the same high school. When I met up with Rachel, she told me the opposite, that it was in fact Peter who cheated on her and broke her heart. She was so angry and hurt still at the time, she had nothing but disdain for him, I remember how she would insult him and her facial expressions when talking about him was nothing but disgust. Both Justin and I were confused and stunned by this since we weren't there to witness this breakup but that two close friends of ours felt so much anger and pain from the other. At the time, all I could do was stay mutual and just hear them out and I continued to talk to Rachel and Peter separately since I had developed a friendship with the two of them as individuals before their breakup. Every now and then whenever I would mention Peter or somehow Peter's name would reappear in the convo, Rachel showed a lot of anger and I could tell it was still bothering her at the time that he did something to her that clearly made her feel like he was the shittiest person on earth. Due to my cowardness and wanting to stay mutual, I didn't really pry into what he did to her since she was obviously angry at anything that remind her of him. But from the small details she did mention in her rants about him, she said that he was very sexually demanding. When I first heard this, I hate to admit but I didn't really know what to do cause I was hearing Peter's side where he said that Rachel was mentally unstable and she caused so much distress and was not communicating at all. So for my sake of not wanting to even think of Peter, my close friend who was really a great friend and did so much for me, being capable of doing something I completely am against. I was 16-17 when this was all happening, and I know that's not an excuse but I kept hearing from the both of them conflicting and contradictory stories, I selfishly didn't want to choose a side. But with that, I made a mistake. Because of my own history of dealing with the divorce and separation of my parents, and having to stay mutual and people pleasing, I thought that if I just didn't choose a side then both parties would be happy. I was wrong.

Around my senior year and early college years, Peter didn't really care that I was still friends and talking to Rachel, and eventually Rachel didn't really care that I was still talking to Peter and hanging out. But I knew deep down, Rachel didn't really like the fact that I was still talking to Peter, since she would still say she hated him, I silently sat listening to this, thinking to myself, if this is how she feels about him, what does she really think about me? I started to feel guilty and I started to feel uncomfortable that I was still talking to Peter and that he got that sort of reaction out of her, but I wanted to keep the image of him being nice and a great friend still intact. So I began to doubt her perspective because Peter and I knew each other for longer before Rachel and I got close. This was selfish of me, I know that now. I started to give into the idea that maybe Rachel did cheat on him and that she was in the wrong, meanwhile still being friends with them. Looking back at it now, I don't know why I choose this other than my own selfishness and fear that my close friend, the person who I had deep conversations about and cheering each other could possibly have been capable of what Rachel said.

It all got to a boiling point around this time last year, the guilt was subconsciously eating me alive. Rachel, Justin, and I were a trio, and we were close than ever before. I would keep bringing up Peter into the conversation somehow because I wanted to make sure Rachel didn't think I was a bad person for still talking to him. Rachel grew annoyed that I kept mentioning him especially since she closed that chapter and is at a point in her life that she can think about him and not really feel the need to get all worked up. But for my own sanity I constantly needed reassurance since I still spoke to him, for my own moral compass to be validated, that I was right and that I was a good person still. Then I exploded. I confronted Rachel and told her I didn't believe her, and that I felt like there was something between us that we couldn't grow deeper in our friendship, that she was holding back, and she admitted to me that she couldn't look past that I was still friends with Peter and it hurt her so much. I told her I was upset that she was distant sometimes, but it makes sense why. If you were still friends with someone who did something so painful to another person, you wouldn't entirely trust them. After this confrontation, I told her I didn't want to be her friend anymore and I cut her off entirely. I do want to note that I did, and maybe still do have a habit of cutting people off or cutting an entire situation off cause I feel overwhelmed and I can't really regulate my emotions.

Today, I regret what I did and said to Rachel since it's been a year. Peter and I's friendship isn't the same as it used to be, and he has done things that have hurt me and changed my mind on him, that I don't feel entirely comfortable with. Things that now make me realize maybe Rachel was right. I'm not defending Peter or excusing him for anything, maybe people change, maybe he made a mistake and grew from it - but whatever he did actions still affect those people After realizing my mistake and how I was actually a terrible friend to Rachel for not standing up when I should have, I reached out. We talked about two days ago. It's the same, but she did hear me out and there may be the possibility of being friends again, but like she told me, it can never be like before.

Has anyone else dealt with something similar?