Oh YUMMEH. That was hot and oh-so sexy! I LOVE Charlie and you characterized him perfectly - a loner, rather easy-going (when things are going his way), that touch of Weasley awkwardness and just so rough and hardy. YUM. I loved that Harry knew all along (the tart!) and the whole premise in general is fantastic, because it was meant to be a purely platonic trip for Harry, but the chemistry was just there. Also this one line:
"Shh," Charlie said, "it's just the dragons feeling the spell. It wasn't enough to get them going, don't worry. Just relax."
Pretty much made the fic for me. EVEN IN SEXING HARRY, CHARLIE KNOWS HIS DRAGONS. THAT IS SO HOT, I DIE NOW.