a match made in hell
An extremely ill-suited pairing of people or things; a match that will result in a particularly negative or disastrous outcome. (A play on the more common phrase "a match made in heaven," meaning the opposite.) I can't understand how John and Samantha are still together—they seem like a match made in in hell to me! Increasingly lax regulations and a money-hungry culture on Wall Street proved to be a match made in hell, sparking one of the worst economic crashes since the Great Depression.