Rorschach blinked and paused when Merope said that she had worried about being considered promiscuous. She used a word that Rorschach typically didn't, "slut", and it made him think. Merope had low self-esteem as it was, and it wouldn't do to make her think that she was something so low after giving him something that had been very meaningful.
"Did care, of course. Are not a slut." the word sounded strange on lips that usually rounded distastefully to produce the word "whore."