A: Mary has been angry with her husband for a while.

B: Why?

A: Because he never took her side when she and her mother-in-law were at odds dealing with the “wedge issue” of child rearing.

Note: A wedge issue is a political or social issue, often of a controversial or divisive nature, which splits apart a demographic or population group. The wedge is a small piece of chopped wood (thick on one end and thin on the other) that carpenters use to help secure two or more adjoining pieces of woodwork. You can also use a wedge to separate things, by inserting the thin end of the wedge into the space between the objects and then prying them apart.