Severus listened to Remus's little speech with an increasing scowl, he didn't believe the other boy for one second - well, about James and Sirius - long experience had taught him he couldn't trust any of the Marauders. The bit about the full moon, on the other hand, made absolute sense, considering Remus's present condition, Severus had known about Remus being a werewolf for some time, thanks to the antics of the Marauders he'd been shown proof.
"You'll have to forgive the over developed sense of preservation," Severus sneered, but not lowering his wand arm one inch, "something you shouldn't be surprised about, considering you played your part in making it what it is. I don't believe you - where ever you are, the rest are. And I meant, why are you in this flat?"