Well, I've been friends with this girl for a while, we study at the same place and see each other constantly (almost everyday).

I know she's like me a lot, but I kinda adopted the "don't shit where you eat" mentality, and we didn't make out or went out, even though I'm sure she wants it.

But for the past few days she's been kinda rude to me, started ignoring me, and just politely (in that mechanic way) says "Hi" to me when we pass by. That classic situation: one day she was all lovable and chasing me hard, the other day she started with this crappy attitude. I believe I did something she did not like, but I don't know what and I don't really care.

My problem is, I'm unsure how to act. When I noticed her attitude I changed my own to "Ignore" as well, but I'm not sure. Should I be the one to confront the situation and say something like: "Why are you being weird and rude to me? If you're gonna keep treating me that way, I don't want to be with you". That's what I would probably say.

But one part of me thinks that confronting the situation, instead of just ignoring her and wait to see if she chases me, is falling into her frame.

Then other factor came up: it's her birthday today. Normally I would congratulate her without a problem, but with this situation at hand, I hesitated and thought about ignoring it and just employing a IDGAF mentality.

What should I do?