Even in the "darker and edgier" stories, Batman can be casual, even mildly humorous -- depending on who's writing. I base that judgment on the arc which introduced the character Azrael: there's a scene with Batman and Alfred stranded in a Swiss chalet.
Big Brother is watching you. And damn, you are so bloody BORING.
Quote:Alfred: ...I've taken the liberty of preparing a spinach fajita.-----
Batman: A spinach fajita? In Switzerland? I would have expected chocolate.
Alfred: A chocolate fajita would be barbarian.
[A few panels later]
Batman: Good fajita. Glad you passed on the chocolate.
Alfred: (Eyeing his own fajita with disfavor) It may have been a mistake. Perhaps the chocolate could work.
Big Brother is watching you. And damn, you are so bloody BORING.