u/Ikigai81

Me and my now ex-partner had been together for about 5 years. Everything had been going well, we weren't perfect and I certainly wasn't a perfect partner but I thought we were happy and I thought he wanted a future with me as we had spoken about many times. I had a great relationship with his family. Last year, after many years of living between our parents houses, we finally found an apartment to move out to. In retrospect, I can see now he was digging his heels in. I had to organise all the paperwork, the packing, the moving. He did next to nothing to help with that until the day of. Once we moved in together I thought this is the next step for us we can finally build a life together. I had been going through university and was in my final year. Then when we moved in together, I felt like our relationship just got very stale which I was willing to work on. But over the months he became increasingly grumpy and snappy towards me no matter what I did. I remember before he ended things he came quite unwell and I tried to care for him and he was mad at me for trying to help him.

Then 2 weeks later, he comes home from work for an hour and tells me he needs a break from everything and that he is not coping in life in general and he is not okay. We had a long conversation, then he went back to work and left me home alone. I was completely distraught at the time I drank myself to sleep that night. 2 days later he comes home again, and says I don't know where we go from here, I just need time to be alone. We never officially ended things it was just a break and that's as clear as an answer that he could give. So I went and stayed with my mum and let him stay at the apartment and I was under the impression I would give him space and then we could talk. But over the next almost 2 months he barely spoke to me. At that point I still didn't know where we stood. All my stuff was still in the apartment. I did not know what was going on. My name was on the lease, he never spoke about me moving out or giving the keys back. So one day I get a feeling that something was off. I go back to the apartment and when I walk inside, one of his younger coworkers is sitting in our apartment watching anime with him. An anime about a girl who has a crush on her manager at the arcade. I kid you not. He was a manager at an arcade and she was his employee. I pretended I had to pick something up and left and he told me they were just friends and that she had a boyfriend and they were in fact going to see him later that night.
Of course, I knew that was a lie. I ended up seeing messages on his old phone and find out that he had taken her out to nice restaurant, just them. On top of that he had been texting her since pretty much the point we had 'gone on a break'. In fact she had been to the apartment many times and had been over drinking with him and they sometimes went out for drives together. Which was exactly how he used to act with me when we first met and became friends. This girl I had previously told him had a crush on him, it was pretty obvious and I remember when I said it he got very offended. Anyway, after that I also found out that he had been texting his coworkers about me walking in to his apartment and was talking down about me to them. Again, I still actually lived there because I had 0 idea what was happening and I foolishly believed we were gonna work it out and even after that I still did.
Months go by, I pretend I don't know anything and after I finish my final exams he reaches out to me and asks to see me. He would text me often, and even sent me gifts. We did not get back together, we had just stayed friends. Apparently that girl had quit work and they were no longer talking. Then after Christmas he ghosts me again, then comes back and texts me again and so on and so forth. he refuses to talk about the breakup or anything related to us from last year yet sometimes still refers to 'us' as if we are still together.
Honestly when I see him he looks like a mess. He can barely look at me, and I'll be honest he looks mentally unwell. Honestly I barely know what to even make of what happened.

TLDR: Long term break up suddenly of 5 year relationship. Potentially cheated or potentially broke up with me to be with another girl but still reaches out all the time to reconnect but won't talk about what happened.