Oh, WOW. Now there's a unique Smutmas gift! ::dies::
Gee, I don't even know where to start commenting on this. I love your cheeky, perceptive teenage Snape, and lonely, kinky Filch. The dynamic between them, the shifting power, is great. But the last two lines..! The very end gives a whole new level of depth to the entire piece. Brilliantly done.
The first view of the castle is gorgeous. Your Filch... is disturbingly sexy. o_O Love their hair, their clothes, Filch's stubble, Snape's wanton pose, Filch's arse with Snape's legs wrapped around him! Abfjfkshfl! Win.