In this case, if I waited, I'd do what I did this time -- digging right through the passive-aggression and problem-solving with her -- but then following up with: "Next time I do something in the house that bothers you, would you mind letting me know as it happens? I don't want you to end up feeling resentful. I know you don't like confrontation, but I swear you won't offend me." Or, alternately, I could ask her if there's anything else I'm doing that bothers her. So my behavior would be showing her that I can handle roommate-issue-related "real talk".