Sorry for the huge wall of text. So me (M) and my girlfriend have been monogamous for almost 3 years. For a long time I have wanted to experience a threesome, even well before ever meeting her. We recently had a threesome with one of her newer friends (F) who she has recently grown very close to. We knew she was attracted to my girlfriend, and my girlfriend was wanting to explore her sexuality after we both got kissed by a female stripper (lol). First threesome was just me and my girlfriend all over the new girl, kissing and sucking. Eventually I asked if I could have intercourse with her and both girls said yes. Others were home so I went slow to not be loud. Gf was on her period so we didn't do too much to her beyond kissing and some rubbing. This encounter kinda just happened and everything from that night seemed to be mostly fine with the exception that I was being too "lovey-dovey" with the friend. My gf said she liked I was trying to make her comfortable, and liked that I was checking in with her to make sure everything was okay, but I wanted to hold hands during certain positions, and I helped her get dressed (my gf was dressed the whole time). To her that was too much, and that is should be mostly for her since that stuff is special. I later explained that I wouldn't continue if I can't be me. Being passionate during sex is who I am and what I want. My past friends with benefits, I did the same thing. I treated them nice. I explained that being passionate with the friend doesn't mean I love her, but I do have some feelings for her, and I don't want to treat people like just a fuck toy. My gf agreed to let me be as lovey dovey as I wanted, but I guess she wasn't excited about it, since she knows that's who I am. We rushed the 2nd threesome pretty bad and didn't communicate anywhere near enough. It was a longer session and a lot more involvement from everyone. Apparently halfway through my gf got jealous and forced her way through to the end instead of communicating if anything was uncomfortable. To her she said she was coming in and out of the moment. Me and her friend had a good time and everything seemed really good and fine. Us 2 had no issues and we connected very well. I checked in constantly with my gf, told her I loved her, and gave her attention. Admittedly I was on an hour of sleep between 2 very long 20 hour days so I probably wasn't being the best boyfriend in this scenario. I should have checked in even more, but my gf also should have told me she was uncomfortable instead of trying to people please and let everything snowball. We tried to be as fair as possible with time and attention among us three, with the exception of my gf didn't want to go down on the girl. No biggie for either of us. Feelings and everything got hurt though from my gf getting overly jealous and not asking us to stop, specifically after I stupidly asked to finish in the friend while in the moment, after me and my gf discussed it being a no-no beforehand. In the moment my gf said yes, and now it haunts her with flashbacks. I feel awful. We didn't communicate enough beforehand or during. There was a lot, but we obviously needed way more communication, and less in pairs of 2, and more as all 3 of us. Thankfully we 3 have been talking it out the following days after and I think we will all still be friends. The friend said the next morning that we should maybe slow down, do some (lots) talking, cuddling, and kissing for a while, to be more comfortable and less jealous; skip the sex for now. I thought that was a great idea. This idea made my girlfriend freak out more. The friend then said she wouldn't mind having a relationship with us (meaning mostly sexual). This made the gf freak out even more. The friend said she has a crush on both of us, and I admitted I have a crush on her. We both want/ed this sexual trio relationship, but don't see long term main relationship compatibility between us, but probably more than just a fwb. My gf on the other hand keeps telling us she wants to be 100% monogamous, no more threesomes. She said she enjoyed some of the sexual things with the friend, but doesn't have a crush for her and the experience turned sour after the fact, even if she enjoyed most of it in the moment. And I think I'm coming to the conclusion that I'm sick of being fully monogamous. I want my gf to be my life partner, but I do want other partners. Watching her being happy kissing/enjoying this other girl, made me happy. Having 2 girls in bed was really fun, empowering, and was some of the best sex I've ever had. My gf said it was hot when I was boning her friend on the first night, second night became overwhelming. I found it hot when the 2 of them were going at it. To me it was better than normal sex in most ways. I feel my girlfriend has deep insecurities that is feeding her jealousy making some instinctual alarm go off, and that's what caused her to not enjoy the experience while looking back on it. My gf is chunky, and the friend is skinny. Gf is tall, friend is small. Just very different body types. For some reason my gf thinks this other girl is better looking and better at sex, which is untrue. I love how both of them look. I tried explaining it that the friend doesn't feel better, but just feels different in an equally good way. I don't think those explanations helped my gf, but it is my honest feelings. So part of me is confused with if she is actually non-monogamous and just scared so she is putting up a wall, or if she is actually monogamous. I love her dearly, and in many ways I have many regrets with how these 2 times turned out, especially the boundary I crossed, but I don't want to be fully monogamous after these adventures. I really don't know what to do. She said she wants to be with me, but she understands if I want to leave her to live this life. I want her to be in this life with me by exploring non monogamy more. I know I can't force her to be non-monogamous, but I also don't think I can happily go back to being fully monogamous. She said if everything went fine that night, we would probably still be having more threesomes, which just adds to the confusion. Part of me thinks it's funny in a depressing way; she gets jealous because she is scared of losing me. Her being scared of losing me, might be the reason for losing me, and it all sucks