Should that really be saner? Considering the context, I would assume that saner men would blush more easily—it would be insaner men who would take such filthy whisperings in stride. Of course, I may just be missing something, for there certainly is an argument to be made that only insane people would blush at sex—

I'd go with the argument that trying to make sense of Sirius's thought processes would be a sucker's bet, at best. *G* His own insanity is his best defense.

As for the sanity of the rest of the world...at least Sirius knows he's insane. The rest of them wear their proclivities on their sleeves and believe everyone else is the crazy one. 9_9