Yeah, the marriage is emotionally dead and she deserves to be happy AND if there was an expectation of monogamy, she’s cheating. If the fans are denying that, it seems to me that they’re taking half the fun out of the storyline (under what circumstances do people cheat and what would be the consequences if she told her husband and how would you handle it if you were in her shoes and…). “She did overlapping serial monogamy because she was unhappy and it was perfectly OK and they all lived happily ever after” is boring.