An eternal puzzle is how a husband/father handles visits by his mother without agonizing conflict between the wife and her mother-in-law.  Here is my Machiavellian solution.  The husband should engineer a conflict with his mother that puts him in the wrong.  Then the wife and her mother-in-law will naturally bond in the face of a mutual enemy.  Don’t forget the key condition that the crime has to be egregious enough so the wife does not come to your defense.  This is why the conflict should not be with the wife:  your mother, being your mother,  is naturally more inclined to side with you.  Added bonus:  husband is conveniently ostracized!