bum-bum

plural bum-bums

1. childish or belittlingThe buttocks or anus.

   "Little Yan Er. It's no good sitting on a boney dragon. You will hurt your little flat bum bum!"

   2023 April 4 (last accessed), Flying Alone, MMORPG: Rebirth of the Legendary Guardian 7 Anthology

   2 more examples

   Kröner sat down heavily, staring at Petra's retreating bottom with its fluttering white bow as she finally continued her rounds, “Lovely bumbum, isn't it, Herr Standartenführer?” he said, addressing James.

   2016, Jussi Adler-Olsen, The Alphabet House, page 86

   Jonathan lies atop Mortimer, who falls backward to the floor. (Martha asks: "Did you hurt your bum-bum, dear?")

   2022, Charles Dennis, “No More Lugosi”, in There's a Body in the Window Seat, page 45