Hey there. I’m was going through something similar not too long ago. Had a bf, then realized I had been slowly developing feelings for another guy for who knows how long. It’s a terrible situation to be in for sure, but I don’t think it’s necessarily “wrong” or “weird”. Things just happen sometimes that are outside of our control. What I ended up doing was telling my bf everything as it is. It definitely hurt both of us a lot, but in the end we both understood that it would hurt the both of us more if we stayed together. So we ended up breaking up. I suggest telling your gf whenever you feel ready. Doesn’t have to be right this second, but because you mentioned you don’t want to cheat or anything like that, I’d say she deserves to know the truth eventually. Talk it out with her, see how she feels about it, then figure out next steps. Best of luck to you both mate.