Hmm I am not sure about this one.

With 2 couples it goes:

Both women know that the other man has cheated but they don't know if their own has. So when the queen says one has cheated at first they don't kill their husbands becuase it could be the other one. But if the other woman didn't know the others man had cheated the cheater had to be their own but since she didn't she must know the other has cheated. So they will both kill their husband after figuring that out.

But i am not sure this is the same for 3 and more couples. Can they make the same deduction? If the queen said that 99 other men had cheated, yes, but 1? I don't see it.