The reason why Fred and his Mother-in-Law don't get along...
Is because they're exactly alike.
Both are loud, pushy, self-righteous, critical, etc...
They say that men marry women that remind them of their mothers and women marry men like their fathers.
But in this case Wilma married a man just like her mother.
I'll bet Wilma took after her father...patient but perhaps a little sarcastic in the face of their spouse.