Green’s Dictionary of Slang

(US) sado-masochistic.

1968		H. Porter Actors: An Image of the New Japan 33: [...] shallow pine-wood trays of fig-sized and insipid strawberries, Peace, Hope, Hi-Life, and Fuji cigarettes, sado-maso-homo magazines.
1972		N.Y. Times Book Rev. 31 Dec. 18: Dodeca, however, is fated to dramatize her author’s sado-maso scene.
2002		P. Anthony Iron Maiden 86: At first she found some of them shocking, especially the sado/maso or weird animal liaisons.