So many little aspects of this I loved: the notion of Harry being sick (and of course Severus having to take care of him), an adult Harry and Dudley getting along (which is something I always believed would be the case in canon -- even if they didn't have a lot of reason to be together, if they ever did meet as adults, it would be friendly), watching Snape torment Petunia (who, by the way, was completely IC even if Snape was just a tiny bit OOC *smirk*), the sweetness of Lynne and the baby, the usefulness of the house elves (saving the day again!), when Harry realizes that the men he finds most attractive are reminiscent of Snape (oh, there's a story in there!), the moment when Snape first presses his body up against Harry's in the kitchen (guh), the sex (of course -- but even better it wasn't just a means to an end for Snape), and the very last line (love that this fic is so circular in some ways). It almost makes you want to feel sorry for Petunia. Almost.
Such a charming, enjoyable story this was -- I wasn't ready for it to end! More, please. ;-)