Care of Magical Creatures by Mia Madwyn
Rated: NC-17
Complete in 67 chapters
Summary: Travel with me back in time to a blissful moment prior to HBP when there was still a chance for our favorite pair to end up together, happily or, um, not. (This story occurs prior to HBP though it might incorporate some knowledge from later books when such details are suited.) Although it has its elements of humor, this will be a dark story so be forewarned.