I’m in a relationship but may have developed feelings for someone else

I’ve been beating myself up over the thought of this but I truly don’t know what to do. I’ve been dating the same girl for 8 months now. I have so much love for her and we share a lot of the same goals and aspirations, she’s very educated and smart and driven like me and feels like the safe option for my future. I do have so much love for her but I’m not sure if i’m IN love with her anymore.

Recently, someone I used to talk to a lot years ago came back into my life. We talk all the time and make eachother laugh and the conversations never run dry. Today we hung out and the whole time I felt the urge to kiss her and I was excited and nervous and had butterflies, things I never feel with my own girlfriend.

I haven’t acted on these feelings as I don’t think I would ever be able to forgive myself for cheating but I’m so confused on what to do, I know I shouldn’t throw away my long term stable relationship for something unsure and reckless but it’s what my heart wants