![1boy 1girl bikini blush breasts cleavage collar covered_nipples darkness_(konosuba) detached_sleeves drooling greyscale grin hair_between_eyes hair_ornament heart heart-shaped_pupils hetero highres holding_leash huge_breasts kono_subarashii_sekai_ni_shukufuku_wo! leash long_hair masochism monochrome ponytail saliva satou_kazuma smile sweat swimsuit symbol-shaped_pupils tally x_hair_ornament zhen_lu rating:q score:16 post #2913813](/cdn_image/preview/ba/01/ba015a24c4db092376769f909dc2ce2e.jpg)
The feeling of lust when a character hurts themselves or is hurt by another character. The image would usually say, "beat me harder!", or something like that.
The term was coined by the psychiatrist Richard von Krafft-Ebing, who derived the term from the name of the author Leopold von Sacher-Masoch, whose works featured this sexual practice frequently.