Stay on your toes and try to keep the kids out of the middle of whatever it is.
I don't know what to say other than be careful and keep us posted...
You know....you could ask her wth is going on?
She owes you that much.
But you can't ask unless you can keep your cool no matter what her answer is.
So imagine the worst case scenario - and see what your emotions are - if you can maintain them, ask her.
Though a certain degree of fear and uncertainly are the norm on THIS playground, it is wrong for your wife to perpetuate those emotions with seeming cloak and dagger behavior that might effect your home and your children.
Stand up for yourself.
But not like a stick of dynomite, exploding everywhere.