gruesome twosome

noun1

1. •
   (humorous) A pair of people who go together, such as two friends, siblings, a married couple, etc., especially if they are mischievous, cause trouble, do not get along well, or have an unpleasant appearance.

   • Lederer and Jackson use a similar system of labels to discriminate the happiest ("the heavenly twins") from the unhappiest marriages ("the gruesome twosome" ) . — 1975