Search Results: girls playing games

A girl I work with from time to time has come across super flirtatious with me in the past. She's gone out of her way to find me and talk to me. She also will come and just tell me random information, or give me a hard time if I don't seek her out. Like she will come up to to me and tell me she only has 15 minutes before she is off.
Although I have asked her out, she has a boyfriend and I know he works in the same building as her. But her manager has told me they aren't in a good relationship, for what that's worth. She avoids me whenever he's at work, but when she's not, she's extremely outgoing and plays games with me and it's kinda weird at times.
My colleagues have noticed and they say a few things.
A. She's playing a game with me
B. She just wants to sleep with me
C. She's keeping me as a back burner

I'm not one to get involved as a side piece, but if things change, wouldn't she do the same thing to me if she wasn't happy, if we were dating?

She's an ex classmate of mine and it sucks because I think there's potential between us but she seems to be playing a very tiresome game. We went out last weekend with mutual friends and hit things off (she was flirting with me hardcore and we were really having a great time) but then suddenly she drops the bomb that she has a boyfriend even though she has never put out a hint of that before. She also gets very triggered when I'm out with my female friends and will send me tons of texts to ensure I'm thinking of her. I'm not entirely sure if it's worth it anymore.

I've been talking with this girl, and we've gotten along super well and we've talked about a lot of things.
She told me she wasn't looking to date or anything, but has mentioned that she wants to do events and stuff with me and teases me when it comes to liking eachother.
My friend said she's playing the game, and she said the girl is showing interest, and I've been myself over the texts and she thinks the girl is doing some kind of game and she's at least interested.
But she also avoids some questions I ask, even if it's nothing serious. She doesn't usually ask for more details about things I'm doing, and even though she insists she doesn't like talking about herself, she does.

Is she just talking to me to be friendly or is she actually interested?