This is a throw away because my boyfriend knows my main blog.
I (20NB) have been in a relationship with my boyfriend (21M), who I'll just refer to as BF, for about a year and 8 months. We're medium distance (he lives in a different state) and recently met in person for the first time last month due to him being really busy. About 7 months ago I met a friend, who I'll call C, while playing a game in a server with some other friends.
Me and C hit it off really well while playing and ended up getting close fast, talking about our pasts and some of the mental issues we have. A lot of our issues ended up overlapping and it made me feel so seen and understood, in a way nobody's ever made me feel before. We stayed up until 3AM for a week straight just talking and messing around in game. Eventually I ended up telling him that I felt like I might Poly, which is something that I'd known a few years ago but suppressed due to some trauma with an ex. I ended up asking BF if I could playfully flirt with C, since I'd been missing my flirty friendships that I had in high school, and he said I could. Recently the flirting hasn't felt as playful, instead being more genuine.
I want to tell BF about the feelings. I don't care if he ends up saying I can or can't date C, I don't even care if we don't end up talking about poly relationships or anything, I just want the guilt of having a crush on someone to stop eating at me. I just don't know how to start a serious conversation because of my anxiety. I originally posted this question to relationship advice but they just called me an awful person, and that's not what I was asking about.
TLDR: Met a friend online who made me feel seen. We playfully flirted but recently it's become more real. How do I start a conversation with my boyfriend so I can stop feeling guilty about my feelings?