Instead of being hurt, denying, defending himself, begging forgiveness, instead of remaining indifferent even--anything would have been better than what he did do--his face utterly involuntarily (reflex spinal action, reflected Stepan Arkadyevitch, who was fond of physiology)--utterly involuntarily assumed its habitual, good-humored, and therefore idiotic smile.

This idiotic smile he could not forgive himself.

Catching sight of that smile, Dolly shuddered as though at physical pain, broke out with her characteristic heat into a flood of cruel words, and rushed out of the room.