Thank heaven for common sense in this corner of the internet! A situation bearing some resemblance to this came up on a soap I follow - in this case married woman began a relationship with her single male boss. She had felt for some time that her marriage was over but hadn't bothered to mention this to her husband. When I dared to suggest on a fansite that she was therefore cheating on her husband, I was shouted down "because the marriage was over and she deserves to be happy". It just seemed so obvious to me that if she was still legally married and the husband wasn't even aware she wanted out, she was in fact committing adultery.