Do u think this was a...?

fling or the real thing??? Ok so i have this friend im 15 she's 14, we were watching a movie at a thirty hour famine, and we kinda were playin footsie, and she was leaning against my shoulder the whole time. Not even during a romantic part of the movie, infact it was a boring part, we basically started kissing, Like serious making out. And we just hung out for like 2 hrs after the movie. just being with each other, kissin and talkin. (at a different movie like 3 months ago, we kinda just held hands and leanded on each other. but nothing really happened. ) It was 1 in the morning, and we were both kinda tired. I liked this girl for a while but i dont know how she felt about me; we have been best friends for a long time. Do you think it was a fling, or the real deal. And if it was the real deal, any tips on how to keep it alive???