GH, Have to say that you are doing amazingly well to keep this under wraps until you feel clearer about how to respond, I am of the breed that tends to erupt immediately when making unwanted discoveries. Anyway, you have received loads of great advice, and you are one others tend to look to for answers, so keep the faith that you will make the right decision when the time comes...
I have to say that I would agree with those who've suggested confrontation, if only to get the cards out on the table, there is much to be concerned about, but maybe the question could be how not if you approach W about it? Maybe if you come to her out of genuine concern for her health and safety, you have already recognized the extreme stress this must have caused her, and it sounds as if OM may be a loose cannon anyway. Maybe your W needs to tell someone what has been going on, and is afraid to?
