I saw a Bugs Bunny cartoon in which he was swapping insults with Yosemite Sam. One of Bugs' insults was 'Your mother wears army shoes'. Why is this an insult?
Yes, big feet. It implies that your mother is so rough and manly that she wears the same boots as soldiers who go to war, rather than dainty high heel shoes. I do not hear the term used often, but I do recall it when I was younger.