I (24M) just found out that my gf (24F) of 10 years has been having an affair with another man (33M with wife and kid) for a year. I've been living with my gf for 8 months now. The nature of her cheating has been emotionally and sexually through online messages. Nothing physical was ever done but that doesn't really make me feel any better when they would flirt about how they wish they were together and she has sex dreams of him.
She met this guy a few years ago playing Pokemon Go and they were pretty good friends. They talked rather frequently, moreso than even I did with her when we were long-distance for 5 years during college (but I don't really enjoy texting, just phone calls). It made me uncomfortable but I also didn't want to be too intrusive, especially because I have over the years had a lot of female friends and it would've been hypocritical to jump to the conclusion that she was cheating. I would even tell friends that I had absolute faith she would never cheat so I wasn't worried. I did believe that he was an emotional crutch for her to an extent, but we would even have conversations about how we needed to work on communication and that I wasn't being as emotionally available as I should have (before you guys bring this up, I know this doesn't mean it's my fault. I feel 0% to blame).
That emotional crutch then became emotional cheating where she was getting what she should have been getting out of an SO from him. We were planning on moving in together after I graduated, especially since it took longer than expected, but I did want to relax for a little bit back home with my parents and all my friends in Indiana before moving to St Louis where she lived. She was getting really pushy saying that she wouldn't be able to handle being alone for much longer and so I fast-tracked the process and moved in with her in September. The problem is that she said she started cheating on me about a year ago so probably around May of last year, so she was knowingly cheating on me while convincing me to drop my friends and family to move in with her.
Before I get much further in the story, I should add that the affair was sexual to an extent. No explicit nudes were shared but there would be teases like pictures in nightgowns or bralettes or playing strip poker virtually and taking a picture of all the clothes that they took off.
We honestly were doing great together. We occasionally had minor arguments about communication or like helping on chores but we were really starting to meld our lives together buying lots of things between us, sharing an apartment, being on the same car insurance plan, and all the other things a couple taking the next steps to engagement do. I was even looking at wedding rings a few weeks ago because I was starting to save some money for it.
Fast forward to two days ago when I rolled over in bed to kiss her and caught a glimpse of her phone where she called him "hun". She's not southern so it wasn't normal. They chatted via Discord and I knew her password because we shared passwords with each other and I looked at her Discord chats with him. I found chats going back to early January. They literally talked every single day, usually boring small talk or about mobile games they played, but I found, on average, an instance of cheating to some degree once every 3 days. She would take pictures of a drink or a meal where I remember where I was when she took them. In April I made a steak and red potatoes dinner for her because she chose that. She sent a picture of that meal to him and said she made it.
In their chats she pretended I didn't exist and he pretended his family didn't exist even though they were both well aware of their relationship status. After confronting my girlfriend and getting her to spill everything she said that she used him as an escapist fantasy where she could be a different person. I asked her why she would send like pictures of a piece of lingerie to him and she said she didn't feel like she satisfied me sexually so she would use him as like a test run. Of all the things that hurt me about the cheating, it's the exclusion of my existence that hurt the most.
So her reaction to being exposed was, in my opinion, genuine and remorseful, but it's clear this was going to continue until I found out because she didn't have the balls to admit it to me. I do believe it started out innocently but she didn't stop it from slowly progressing to something inappropriate. She says she's willing to change and repent to whatever degree is necessary because she says she loves me. I don't know yet whether to believe it or not. She said she will never talk to him again, stop playing social mobile games, let me see her phone whenever she wants, anything to let me trust her.
I'm a naturally trusting person and honestly the trust isn't as big of a hurdle as thinking back to all the moments we had in the last year that were tainted and every "I love you" from her being not wholly genuine. I know I'm really early in this process and I've even had lots of changes of heart in just a few days where I can't even eat and sometimes start shaking uncontrollably. I did love her but this was for so long and so secretive that I told her there is no option but for me to leave her whether I wanted to reconcile later or not.
So where I need is advice is where I'm at mentally right now. I have no doubts about wanting to leave her. I've already told friends and close family, and planning to move back to my parents in Indiana by next weekend. I do also plan on doing basically an exit session of couples therapy with her to maybe shed some light on possible growth for both of us, regardless of our future. After 10 years and a real solid outlook on how we wanted our life to go, I find it really difficult to flush it all down the drain. Is it wrong of me to have the desire to recover from this emotionally on my own time so that a reconciliation is possible? I know that no matter what if we want to get together in the future, I'm not going to be the one to stick out my neck. I already sacrificed and got burned by her so she would need to do everything to convince me she's serious.
In conclusion, I am having a hard time with memories and feelings like I wasted an entire year with someone who didn't love me. That being said, I know that growth is possible. Am I a fool to want to get over this and want her to grow so that we could start anew? I know the relationship would be different, but it's really hard to not at least think of the other 9 great years we had where we stuck it out through really tough periods of long distance, to the point that we were the most rock-steady relationship many of our friends strived to be. I tried posting to reddit but didn't get many thoughtful responses, and many assumed things I didn't say in the post. So hopefully here is more insightful.