So technically we were not "together" but we've been sleeping together for almost a year. We were friends for years before that, and we both said we loved each other, just wasn't sure about a relationship. Now the woman is not my mom, but she's been like a 2nd mother to me since I was 12 (I'm 23). So, the three of us hang out all the time. I completely trust both of them. That is until one morning when I caught them in bed together. So, if we were never technically in a relationship can it even be considered cheating? Do I even have the right to be mad?

There's actually more fucked up shit to add to the story. Let me know if you want details.

OK so details, this actually happened on Thanksgiving. and I went a month without speaking to either of them. when it happened she was joking about it, saying they broke "bro code" and that of it made me feel better it wasn't good. at that point I hadn't said anything, I was kind of in shock, when she said that I went off, and then she changed said she was asleep the whole time and that it was rape. after that I left, and she texted me everyday saying she was so sorry and that she was really drunk and had passed out and was asleep the whole time. so I finally talk to her and she does admit that she wasn't asleep the whole time that she did wake up in the middle and told him to cum in her. she told me it was the biggest mistake she'd ever made and that she never wanted to hurt me. so I forgave her, but then a couple of days ago he calls me. (first time I've talked to him since that day) he apologizes to me and I tell him everything she's told me, he says it was never rape, that she's the one who got him to follow her into her room. and that they didn't again after I left.

now I'm not the one who trys to make a bad thing work. I've had no problem dropping people in the past that have done me wrong, but this is different. he was my best friend, and she's been more a mom to me then my actual mother has.