Sharing my girlfriend went wrong
My male primary partner, J, and I have been together for just about six years now. We opened up almost a year and a half ago. We first ventured out in the swinging community but have since branched out to where we do separate, as well as couples, dating.
I am bisexual, and it was very important to me to be able to experience dating women as all of my previous dating experience had been with men. I started dating a girl, Lacy, about three months ago. I clicked with her really well, and we were really attracted to each other. Lacy has a boyfriend who was comfortable only with her dating women, but not other men. J and I invited her to go on a trip. Looking back, I definitely see all of the things I could have done much better. I should have waited longer before inviting her on a five-day trip. I could have asked her what she was comfortable with, and how she was feeling about our relationship. But I didn't do those things. We ended up having a few spectacular threesomes with her, but I started feeling really uneasy. I felt: if this person who I have seen only for three weeks is willing to cheat on her boyfriend of two years, how can I trust she won't lie to me, too? And then: she and J decided they wanted to start seeing each other.
I was not prepared for a triadic relationship. It's not what I wanted when I set out to date women. The relationship between the three of us became way too integrated and warped, and I started feeling like she was being manipulative. She started saying one thing to me and another to J.
I broke up with her, because I realized I just couldn't trust what she said to me and I felt emotionally manipulated. J is still talking to her. He has said a few times that if he just needs to cut her out of his life for me he will. But I know that she is also someone that he has connected with extremely well and I feel guilty asking him to stop seeing her. I also know that every time they talk or see each other or I hear her name or I know he is texting with her, I get nauseous and depressed. I am sad because: 1. My relationship with my first girlfriend ended, and 2. My primary partner is choosing to have a relationship with someone that I see as manipulative and untrustworthy. The other thing about that, is that J agrees with me that he sees those characteristics in her. So I get extremely confused as to why he would continue wanting to have a relationship with her.
I have always had a more difficult time with J having separate partners, because I tend to feel excluded. But this situation just takes the cake, because my relationship with her was very meaningful and now I don't view her as an appropriate partner. Am I being unreasonable in feeling that he shouldn't see her anymore? Are there perspectives I am missing?