I am coming very late to the ride here, but goodness am I thrilled that I have found this (via painless-j's rec at the Know-It-Alls archive: http://mujaji.net/kia/). What a quiet, moody tale of obsessive love and self-identity. The tone seemed sedate for the story it was telling, but the passion that lurks just beneath the surface snuck up to ensnare me each time I began to question the atmosphere. That scene where Harry confronts Snape with the realization of his identity, where Harry lays it all down ("Then remove your glamour" had me gripping at my desk) and they have it out - gahhh, I would not trade that for the entire book of Deathly Hallows.
And Harry. Oh, Harry. Moments like when he Obliviates his own mirror or when he desperately reminds him or Snape that he loves his kids - those moments chill me a little. He knows how dangerous it is, he even knows how "wrong" it is (which can be inferred from his wondering how something so right could be so wrong), but our impulsive, emotionally-driven Harry would not stop this plunge if he could. (And I think he could, if he were anyone else.) His addiction to danger is a fascinating, very apt point to bring up. It's always been there, hasn't it? And the circumstances of his childhood and of his growth can only have nursed the urge. It isn't likely for him to slip easily into a placid, staid family life.
You do a wonderful job with their characterizations of course, but much more than that, what really makes this whole piece so dazzling to me is how well you capture their characterizations in relation to one another, in their interactions. I don't know if this makes any sense at all, but my point is, you really make me believe that they need each other, that they can be truly and honestly themselves only with one another. Every scene reinforces that for me, from Harry's itchy passivity with Ginny to the relaxed tension between him and Snape. By relaxed tension, I mean an off-kilter mix of banter, sexual tension, and deep, very deep understanding. That's what I get from these two in this story, and despite how many Snarrys I've read, I rarely get the sense that the relationship is Right, as I do here.
And of course, the exploration of Snape's body all throughout is gorgeously sensual. All the details woven with such pure indulgence on Harry's part - Wow. I had to remind myself to breathe quite a few times.
The last thing I would mention is the Ginny treatment. I want to serenade you, sing you every adulation I know, for how beautifully created she is. I can't really understand her, but I cannot dislike her either (your writing just does not allow me to), and I'm willing to overlook any opaqueness to her character because of how well strangely bland works for her, emphasizing Harry's need for something darker.
I know there were several other things I was thinking about as I read, which I'll later regret for not remembering now, and there is a lot I know I've missed as well; when I reread, I'm sure I'll find another handful of jewels in your writing. This seems to be a story that ferments and grows sweeter and richer with each taste, so I'll just stop here and thank you for a really brilliant and enjoyable story. :D