If I was in the same position I might just ask 'So your wife is a strong willed woman and it seems like you're treating her as a servant, what do you think?'
Thinking about this, with the most recent case. I definitely didn't see myself as running an OC style campaign. To me it was a Gamist/Sim sandbox where effectively navigating the political goals and the emotions/feelings of your (Mastermind Rogue) wife was just as important as navigating dungeon corridors or court politics (which the player was also very bad at). But there were three PC/player groups in the sandbox. One lot Old School Gygaxian geezers, one sort of very easygoing light OC, one went hardcore OC and started rejecting GM determined facts about the world/setting. They just went on a completely different page. But I certainly could have tried to head this off rather than let it run on for weeks.