My mom tried having sex with my brother, now I want to have a poly relationship with them

My (16F) mom (51F) and I are really close, I can tell her anything I want, and she's never judged me or anything like that. About two years ago she told me that she was a little depressed, and she also told me that once she was married she never had any other sexual partners. It seemed like she was lonely, and I wanted to show her that she doesn't need to worry so much about a relationship if she wants to have sex once in a while.<br><br>I decided to show her that she doesn't need to have a relationship to have sex, and we had sex for the first time. I was a little afraid at first, but as soon as I started, I instantly felt a lot better and she seemed to as well. We have had sex off and on for about two years now, and I was never really afraid or hesitant about it after the first time. <br><br>I have a brother that's 12 now (I'll call him A) and he was 2 years old when my parents divorced. He has no relationship with our father, and my mom hasn't had any new relationships, so she has always been focusing on him and me. I think he's the reason she was so lonely, because taking care of us has always been more important for her than a relationship.<br><br>Last year my mom told me that she wanted to have sex with him. I knew she probably wanted to have a sexual relationship with him at some point, because she's said plenty of times that she wants us to be like a normal happy family where everyone has sex with everyone else. I wasn't sure how he would feel about it, so I told her to slow down, because I didn't want him to feel uncomfortable.<br><br>Then one night we were all in bed together like we usually are, and my mom showed him her vagina. After that they've had some sexual contact, and I was glad that she had finally been able to show him that love. <br><br>I'm 16 now, and he's 12, and I think ever since I had sex with our mom, it's made our relationship closer and more loving, and I saw that when I watched him and our mom have sex for the first time. Now he seems much more confident and happy, and I'm really glad he got to have that experience. <br><br>After seeing him have sex with our mom, I realized I have sexual feelings for my brother. I want to have a relationship with him and our mom together. It seemed weird at first, but the more I think about it, the more I realize this is a natural feeling. I want us all to have a happy and sexual relationship, and I want to show my brother that same love our mom was able to show us.<br><br>&#x200B;<br><br>Edit: I show my mom love and have sex with her because I love her, not because I was abused as a child or something like that