If we try to get rid of a counterfeit coin by passing it off upon somebody else, sooner or later it will find the way back into our pocket. Figuratively a bad penny is a ne’er-do-all-well, the black sheep of the family. We use the proverb in reference to a young man who leaves home in disgrace and returns there after a long absence in the hope that all is forgiven.
A man said to his companion in a public house:
‘Who’s that down-at-hill fellow propped against the bar? I seem to know his face.’
‘Don’t you remember him? That’s Alec Palmer, the drunken oaf. His father threw him out years ago. When the old man died he sneaked back home to live rent-free and spend his mother’s pension on beer. A bad penny if ever there was one.’