The phrase, "living over the brush", used to describe an unmarried couple who live together, originated in the tunnel building days of the 19th Century. If a boy and a girl (usually camp followers from the towns, prostitutes in reality) took a liking to each other then the other men and women would respect them as man and wife. They could not afford a church wedding so, holding hands, they jumped over a brush or broom handle held by two older people. They were then "married" in the eyes of their peers.
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