<human>: Can you give me a shortened version of the text?

So, just as some back story my girlfriend and I have been together for just over a year and a half. In that time I have stayed emotionally close to her but I sometimes find myself growing towards another person. This usually ends as I don't think I am not in love with my girlfriend any longer. Well, this girl [20F], that I've always found attractive and had a small crush on since early high school, and I have worked together for a bit now and finally gotten the chance to actually talk and I've fallen for her more. She has also expressed having a crush on me as well.
Albeit, we both have a smaller crush on each other I still feel myself growing more for her. I haven't expressed this to her nor my current girlfriend but I don't know if breaking up with my girlfriend is a good idea since we've been together so long. My girlfriend and I are still very close emotionally but I have become increasingly curious in how a relationship with my high school crush would go.

Do I leave my girlfriend for the possibility of a good relationship with my high school crush?

Do I ignore it in hopes of it withering away like the much smaller instances I've had before?

Why would I, someone who's emotional connection with my girlfriend hasn't withered, find myself becoming emotionally connected with others?
<bot>: My girlfriend and I are still very emotionally connected but I've found myself growing more emotionally connected with my high school crush and I'm not sure what I should do.