In love with a girl who is my friend's(co worker, not a close friend) ex-girlfriend!

So it started when I got a part time job in my college. This is a job where you have a partner and you stick with them for 5 hours to roam around dorms in college to check whether everything is okay ( Mainly to spot weed and booze, which we never do ). I met her in the orientation, she was so cool and I fell in love with like the guys in John Green novels. To my disappointment, the same day I came to know that she has a boy friend and he works with us too. (They always work together as partners) I didn't want to do anything with their relationship and I would just admire at her beauty from a distance. But soon I became friends with her and so her boyfriend. Her boyfriend and I were both not from US but from neighboring countries so we got along in a way. I didn't really like him but just for spending more time with her, I tolerated him. Some days when I got really lucky that she and I were in the same shift together in which her boyfriend wasn't. During those times, we were became( I think, not sure about her) good friends, we talked for hours during our shift. It is not like she or I had a choice, we were forced to spend those 5 hours together. We had several similar sessions like this and we became good friends.

I came to know that we had several similar interests like music, tv shows, yoga, running and other good stuff. I knew that she was so awesome when she said she likes Regina Spektor ( all my friends make fun of me for listening to her). And for weird reason, she thought that I really got along with her boy friend and made me hang out with him a lot. Her boyfriend was a fucking possessive asshole. He wanted to break up with for some silly reason. And they both came to me for some unbiased option( which was ridiculous). I really really liked her very much but never made a move on her just because I was friends with both her and her boyfriend and knew them. And then I graduated and moved somewhere else while she was still in college.

We didn't talk much after that at all. May be a couple texts here and there. After like 3 months, I got a text saying "myname, I miss you" from her. Obviously I was fucking happy but not sure whether she meant it as a friend or more. Then I started talking to her a little and then she told me that she broke up with her boyfriend. Then I really started to suspect the real meaning of the "I miss you". Still I didn't want it to be awkward, so I made moves a little slowly ( maybe that's a mistake). And there wasn't really anything I could do, I moved to a different city. She was still in college. But I wanted to meet her and go out with her at least once. We texted from time to time. So I went to meet her, grabbed lunch together. And also then she invited to go to some state fair with her friends. We went and I really had a great day and time with her. We didn't hold hands or kiss or anything like that at all.

Then I came back to my place and we texted for a few days. And nothing else. I tried texting but didn't want to annoy her too much. There's always a fine line between showing interest and annoying her. But still when I see her pop up on fb feed, I feel so attracted towards her. She's still single and I want to do something to develop a relationship with her. But I have no idea what to do. All I know is that I really really like her.