Wheee, I loved this! Percy is so... Percy (doing research in the bookshop, being so adorably flustered, taking things *seriously* because that's what he is, and the way he orders Oliver to fuck him. Wow, that was awesomely hot). And the last line reduced me to wild giggles. Ohyes!
And I loved Cedric/Oliver changing room sex with them betting on Quidditch outcomes (one of my fave scenarios, really).
There were a lot of little details strewn in that made me happy - from the 'Uvul the Unicorn' books (for the girls) to Oliver's "I have to go, or Harry won't eat".