Awwww. This was fantastic, except that I'm kind of mad at the Whomping Willow for enticing Remus like that and then having the audacity to be angry afterward. Not far at all!
The last line was perfect, of course.
And, oohhh, this line: It had been so long since he'd been with anyone who would play those kinds of games. Who played those kinds of games, then? This must be explored in more detail, methinks!
I also really loved this line, even though it was heartbreaking: Of course, most people would think his worst nightmare would include him turning someone into a werewolf; that wasn't simply a nightmare, but an all too real possibility.