29/M I slept with my ex wife 29/F, now I have to tell my girlfriend 31/F.

At an early age(20) I had my first child with my on again off again high school sweetheart. After my son was four months old we got married. We had some struggles and eventually had our second son in 2021. Two month after he was born my then wife filled for divorce. Things got rough in court, but after two years we were finally divorced. In November of 2021(four months after my separation and full swing divorce) I met my now girlfriend. Back then we were just fooling around and it really wasn’t bad at all, but I was ready to cut things off by end of February 2022. Because I was not emotionally ready for a relationship and wanted to go through some therapy and be fully committed to my kids. Well come to find out this woman was now pregnant, and she didn’t know if it was mine or not. As she had been seeing someone else too. I decided not to say anything just yet because we agreed to do a DNA test after the child was born. We continued to stay in contact, fooling around a few times, until the child was born in late October of 2022. It took a while for us to get the DNA test but I was in fact the boys father. UNBEKNOWNST TO ME!!! The other possible baby daddy was there for the birth of my son, and even though he didn’t know if he was the father he still signed the birth certificate!(I unfortunately was not there because I’m an idiot and didn’t go.)Eventually my now girlfriend relocated two hours so that we lived closer and I could have a relationship with my son. We had continued seeing each other, but kept an open relationship. All the while I was very involved in my other two son’s lives and paying child support to my soon to be ex wife. By the summer of 2023 I was divorced. My now girlfriend and I had moved in together and were expecting a daughter, born in early 2025. Fast forward to March of this year, my now girlfriend and I had discussed moving back close to her hometown(2 hours away from any of my family and putting me 3 hours away from my older two boys) where most of her family lived. I was hesitant and not a big fan of the idea but because of how much I wanted her happy and love her, I agreed. Now last month she got a job offer in the area we were trying to move to. We still have not found an apartment so she thought it best to take the kids and stay with her mom until we could get an apartment. I have been staying at my mother’s because there isn’t enough room at her mother’s house when I have my older son’s. We really haven’t gotten to see each other much the last month but we communicated daily and FaceTimed when we could. Now I’m very irritated about how we left our old house because my girlfriend decided it would be best to save money and not pay the rent or utilities, saying “we should have a place before anything happens.” And that has not been the case. So now for the last month I’ve had to go to our old house and clear everything out. With the power getting shut off there was obviously a lot of gross and disgusting things I won’t mention. I was the one to handle everything because she was working full time while her mom kept the kids, two hours away! So yes I’m a little salty! But now for the main plot point, about two weeks ago while exchanging kids with my ex wife she mentioned her and her short term boyfriend had broken up. She mentioned this because the boys had gotten attached and might still be upset. I thought nothing of it until she texted me asking about or son’s. In conversation I asked what happened? Just trying to be polite and make sure she was okay. She told me she just didn’t love him, this led to us having a conversation about letting new people get to know our kids so soon. We eventually started to talk about our marriage….and some things we haven’t discussed in five years….to which made us a little more comfortable talking….so we kept texting through the week. Nothing crazy, just talking about our kids and things we did wrong in our marriage. When we met at the end of the week we talked about a few things and hugged. When we started to pull ourselves away we had locked eyes, we hadn’t been that close to each other in five years….and we shared a kiss. I’m not talking about a little kiss either, there was some passion. After leaving we gave each other some time to think, then after the kids went to bed we talked on the phone. We admitted things that we had buried during or divorce, neither of us actually wanted to get divorced….and we still had feeling towards one another. We were pushed into the divorce by our respective families and let others speak for us. After a few days of us venting about our emotions and clearing the air we needed to talk face to face. We talked for a long time. About everything. But this led us to another passionate kiss, and then we did what two people do when they open themselves up to each other. By the morning sun she had left and we both knew I needed to tell my girlfriend what had happened. It wouldn’t be right if I didn’t, and I couldn’t move with her because I’d be denying everything I felt. So now I need to know, how do I tell this woman that I love that I can’t move with her? That I still love my ex wife and we have done things that we can’t take back….not that we want to. P.S. My ex wife and I don’t plan on getting back together, at least not until we can talk through our issues and both do some respective therapy.