really need advice about a girl (College)

-This girl and I are freshmen in College
-She has had a boyfriend for about a year and a half. He goes to a community college about 15 minutes away.

So I've been into this girl since the first semester, and still interested in her this semester. I DO NOT want to come in-between her and her boyfriend, but If they were to breakup she would be one of my top choices of girls I want to date.

We don't hang out or talk consistently. Kind of have times where we won't talk or text for like a week or two unless we pass by each other, but we are always happy to see each other. Sometimes, like this week, we hung out almost every single day for like a few hours.

When we hang out its usually like watching TV or studying (but we tend to drift off from studying and just talk about stuff). I try not to flirt too much because I don't want her to feel like I'm being to aggressive because she has a boyfriend. Ill do little friendly flirts like make strong eye contact, give her a hug when a see her, high fives, and "accidentally" brushing her arm or something

Two nights ago she left her hoodie and dorm room keys in my room after we studied and watched some TV. Im not sure if she did this on purpose so she could stop by the next morning (I like to think she did, haha but realize that may not be the case)

Basically I would like advice on what I can do now in-order to be a potential boyfriend if she were to ever break up with hers. I am not only focusing on her a potential girlfriend, but I feel like I have had a better connection with her than other girls that I'm thinking about dating. I don't know what to do because I don't want to be too passive and get stuck in the friend zone, but at the same time not so aggressive that she gets confused and loses interest in me. I also don't want to cut her completely off since I do value our friendship...but after we hang out for even an hour, she gets stuck in my head for the rest of the day.

It's a losing situation. Even if she breaks up with her BF, you will end up being a rebound guy, and if you wait instead, some other shlep will be the rebound guy, then she will go back to her ex because she misses him too much. So like I said it's a losing situation. My recommendation is to stop wasting your time with girls who have BF's. You are in college there must be tons of single girls out there.