There are 17 Thousand stories in here a not a single one has darvin in any kind of plot
otherwise
They didnt show any affection towards each other in the movie, like no at all
So before you do this build up the character a little

Ah, I'm so honoured that you wrote me such a cute little fic for one of my favourite pairings! :)

I do like this little canon divergence as well! Of course, everything could have happened the way we saw in the movie only for Darwin to come back later, but this works too and avoids all the angst of everyone thinking he's dead.

I do hope Darwin's hand stops hurting, but I suppose Alex's kisses will help with that. :D

With Darwin still feeling so dazed, a line like, "My lips hurt," fits. :) I mean, it's a silly line, but you've established pretty well just how dazed he's feeling after what's happened, so he wouldn't be thinking of clever lines, lol. And I'm glad Alex and Darwin weren't too embarrassed and that they were able to comfort each other and admit their feelings! :D

I don't mind short at all, for the record; I love short fics, so the length is perfect! :)