AITA for being in love with my friend while having a gf?

as the title says! i (f20) have been in a pretty serious realationship for 3 years now. Me and my girlfriend (f23) rent and apartment, have animals and almost all of our friends are both of our friends. i would say i love her, i do a lot for her, she is suuuper gorgeous and i know her family (even though we are not out to our families). Then there is another girl. She is my age and also has a girlfriend, living in a very similar situation as us. I have known about her for longer than i have known my gf. If i would have known that she also likes girls before i met my gf, im 100% sure that we would be together now. There have been moments that i could write done as flirting from her side. We ussualy hang out together in a larger friend group, and most of the time there is a moment when were, to the best of my explinaton, both alone in a crowded room, we just laugh about nothing and stare at eachother for a moment, then just kinda shift back to the setting that we are in. There was also a time when we were having a sleepover type party in another friends house and we were that last people left downstairs, everyone else was setting up to watch a movie, we were both looking at something in my phone and talking, then my girlfriend came to call us upstairs and jokingly said “stop flirting, you both have girlfriends” and we both just kind of akwardly laughed.

Im pretty sure that ive been thinking about her every day for about 2 years, sometimes less, but right now ive havent been able to sleep without thinking about her and us, even have had dreams with her in them.

Another very important part is that she has told me and my gf ( i would say we all are in the approximity of all being best friends, but then a gain we have a pretty large friend group) about stuff that her gf does and she doesnt like, i dont want to go into that because thats just another paragraph and not that important. Based on that, a couple of times me and my girlfriend have had a discussion about their realationship, in which we came to the conclusion that something is not right there and they propably will not last very long, and both me and my girlfriend said that the girl in question is very attractive, but that is pretty normal for us, as we have agreed to an open realationship, just none of us have acted on it at all( that including other people that are not this girl) .

Ok, last thing i think. I got together with my girlfriend when i feel like my brain was not fully developed, she is my first girlfriend, and all this time i feel like i should have maybe said no when she asked me to be her gf. She is lovely, dont get me wrong, but almost every month there is a week when i think about breaking up with her, and how hard that would be, but the feeling ussualy passes, sometimes it hangs on. She is also very senstive, she always says to me that she wants to marry me, i do not want to marry her, i try to tell her as gently as possible but she still gets sad every time. Also, it is very hard for me to say no to her about things like moving in when we move to another city for studies next year (also the other girl is moving there propably). She is very understanding and we both always say that communication is important but i feel like i wouldnt be able to tell her that i want to break up, she would be super sad and i dont want to hurt her, the one time i tried to bring up something like this, she got, again, very upset and it just ended up with me apologizing about it ( i feel like i apologize a lot to her about meaningless things.)

Ok i think thats it, my question is should i break up with my gf and maybe try pursue the other girl even though that would flip all of our pretty good lifes inside out and upside down?

Also does this even sound logical, or do i just have a delusion about her maybe liking me back?

Please ask aditional questions, i feel like i couldnt type out everything.

Thank you so much if you read this and have any insights, i really need that and appreciate it :)