Hi lovely people of reddit. I've put myself in a weird position and I'm unsure how to go about it, so I'm hoping people who have been in the same situation, or perhaps just a different look from this community will help.

       So, I don't want to get super specific. I honestly don't know if my boyfriend follows me or not and I genuinely don't want to hurt him in any shape or form. This has been weighing on me heavily and I'm unsure how to approach a conversation like this with him. Me and my bf(B for simplicity) have been together for about 3 years now, we have plans to get married this year, talked about our life, etcetc. I'm a straight female, B is a bisexual male. I have absolutely no doubts in my mind about him. I very honestly feel very fulfilled, in-love, cared for etc with him. I've always been a very monogamous person, I'm able to admire people, but no one has ever sparked my interest when I'm with someone; even when I have been unhappy in pat relationships. I'm simply a very loyal person, and I have no desire to stray.  

      So, I recently met R through a mutual activity me & B do. And I have NO IDEA WHY but something about R just...*CALLS* to me. It's the same feeling I got when I first met B. I honestly get the same...'zing'. This tingle in my chest. I get butterflies when I see or talk to him. WHY OMG. This has never *EVER* happened to me. I'm legitimately so confused...and I couldn't stop myself from talking to him. I have learned that R is also a bisexual male...and yes in my honestly perfectly selfish world in my head, I would love all three of us to just...be together. I've always joked about brother husband's. Idk why, the idea has always been somewhat appealing, but I also never really took it seriously...until this moment.  

          Now I swear, while yes I have mildly flirted with R, which me & B have already talked and flirting is okay as long as it's not sexting, etc. I have done my best to keep it platonic. I did admit to R my feelings, and that it may just he a crush because of the attention I get from him. He knows I'm in a serious committed relationship with B, he knows the lines I refuse to cross. However, since B is significant other, I feel like I'm hiding something from him, and its disgusting. He knows *OF* R. He knows we're friends, and they briefly communicated in a group activity, related to our hobby. I have other male friends, so that's honestly not the issue. I want to tell B that I have feelings for R, but I really don't want B to be hurt by that, like...feel like he's lacking, or he isn't giving me something which *ABSOLUTELY ISN'T TRUE AT ALL*. I bring this to this sub because I do know that B HAS been in a trio/poly relationship before. But I know it ended badly. I don't know the entirety of the details, but I know it is 1 female, 2 males, unsure if the males were sexual or not, and it ended because B basically ended up feeling like a third wheel on their relationship and it got awkward, and jealous, and unfair etc.   

              So..I'm unsure how to approach this...I know I have too, I feel too guilty not saying anything to him. Does anyone have any type of advice? Thanks. 

I also apologize for the formatting. I'm on my phone & tried my best. 😅