<human>: Summarize the given text in a few sentences.

Ok, so ill get right to the point. This summer, i(male, 19) met someone that changed my life. I got a ticket to go to a concert with my brother, and we ended up getting a ride with a mutual friend and her friend(female, 18). We ended up really clicking,  the friend of a friend of mine, and we kissed, etc. I only had about three weeks left until i returned to university 3000 miles away, so i wanted to make them count. We spent some awesome time together, time i wouldn't take back for anything. After a decision for me to move back home for a lot of reasons, i asked her to be my girlfriend. She wanted to wait until i was back to see where we were at. 

However, apparently someone who had professed his love for her many times but due to the fact that he was always either out of state or she was in a relationship, they never got a chance i guess. So currently they are together, and here i am. 

My question is this: do i have any sort of right to try and pursue her still? I dont know how he treats her, but she has told me (weve decided to stay as close friends for now) that he has been very unreliable in the past. I would never ever cheat or be the person someone else cheats with, so thats not an option. I also know that she still feels the same way about me, just from how weve interacted since then. But what can i do, if theres anything thats not morally appalling, to win her back? I don't want to hurt anyone, but i also dont want to hurt myself. Shes the only person ive even considered as a relationship prospect in years, and i dont feel like i can just give up.
<bot>: met a girl at a show, asked her out, she wanted to wait until i got back from university. Someone from her past came back, theyre together. Do i have any sort of right to try and get her back?