Oh! That was wonderful. I loved your Snape, willing to do anything to ensure that Harry stays, and Harry not wanting to change anything in the house in fear that Severus would oust him, and Draco barging in, interpreting for them. Delightful.
Snape's description of what he imagined Harry and Draco doing was... guh! Unbelievably hot.
But my favorite thing, by far, was Snape's sort of contented surrender at the end.