Not bad for a first fanfic--reminds me of my first attempt. A couple things, though:
You seem to be shifting between past and present tense a lot, which makes it confusing and hard to keep track of what's going on. Keep it consistent.
I also suggest you work on characterization and content. The personalities are fine, but the dialogue seems choppy, and it just doesn't feel like the characters. I highly doubt they would make decisions as important as that in a few seconds, so you could easily expand the dialogue sessions.
Otherwise, I like it.