You think Snape will ever share his other forbidden memory? The one where he says to himself, "The day he felt anything but contempt and utter loathing for Potter was the day he'd dress in pink and sing 'I'm a Little Tea Pot'."
Heee... I have a feeling that Snape won't even want to let himself so much as think about that little promise.
Very nicely done. You almost had me convinced that Harry would walk away and that Snape would let him.