Lovely build-up of the relationship! I wonder now if Harry was just "faking" the interest in Potions in order to squirm his way into Severus' space. *hums* If so, clever. Not that Severus seemed to mind. ;-)
I loved this description of Harry for some reason, particularly the 'blended in just enough to not stand out': This Potter walked with an air of assurance – not bravado or egotism like Malfoy had, but that of someone with a quiet confidence, who blended in just enough not to stand out. This Potter had developed grace on his feet that matched his skill with a broom. This Potter was desirable, Severus realized.
And this was hot: He wanted Potter in every way possible