"Because I'm not a monster," Malfoy said.   He set his glass down on their table with a loud clunk and the remaining whiskey sloshed up one side.  Hermione stared at it, unwilling to meet his eyes for this question.  "I've known several of them, and I choose not to be one."  He added what sounded like forced joviality to his voice with, "And it's hardly a burden to share a flat with a reasonably pretty woman.  I've suffered worse."