Oh, that was so good! Great use of the prompt, and a charming exploration of the relationship and of Harry's little quirks. Very endearing. I'm very glad of the happy ending. :)
I'm curious about Harry's peculiar aura that Severus noticed, though - that was never really explained; if it had any sort of long-term effect, if it was what allowed Harry to see Severus or if that was merely coincidence, what caused it. I'd love to know.