I am briefly at a loss for words. That was really hot, for starters. *fans self* And everyone was so IC, I felt like I was reading the missing canon story. The dorm and the lonely holidays and the Great Hall put me immediately in that mindset.
Even though I knew this story was angst, I still read it thinking (hoping?) it would not end badly. Someone sure needs an arse kicking though. (I'm looking at you, Snape.) Maybe I'm just too accustomed to reading Snarry with happy endings, but Snape really had me convinced that what he was doing to Harry was enjoyable for him as well. At least enjoyable on more than a "I'm just using you in the worst possible way" level. My mind fights with it even now -- why prepare Harry slowly and coach him through his first time if only to humiliate him later? And Snape would not be able to fake the arousal in his voice.
See, I'm trying to convince you this should end happily -- it's what Snape really wants. He's just too stubborn to see it. ;-)