What is the meaning of this relationship?

Hi, I’m 20(M) and my college classmate 20(F), She already have a boyfriend and I’m Single, We’ve been more attached recently(2months) like looking eachother at class time! Yet we tell ourselves that we are friends. She also said one time she has a crush on me! and i didn’t take that seriously that time! Now she’s getting jealous when I’m watching another girl in front of her and she says “Im gonna accept that guys request! I’m gonna talk to that cute guy” to also make me jealous and yes I’ll also have jealousy when she talk to my same class boys.One more main thing that Me and her having same vibes and same aesthetic.She is attitude girl towards boys but so far not to me! Whats the meaning? And I don’t want to get into deeper like she brokeup her bf just for me or something like that….What do I do? I just wanted to stay with her as a friend maybe bestfriend no more no less…..
Please i need some advice and sorry for my bad English.