come back like a bad penny

To appear or return regularly, especially of a person or thing that is unwelcome or objectionable. I'm sure we haven't seen the last of your conniving cousin—he comes back like a bad penny. Political scandals like this one always seem to crop up every few years, coming back like bad pennies. A: "I don't think we'll see Todd again now that he's been disgraced at work." B: "You never know—these guys sometimes come back like a bad penny."