cruel mistress

plural cruel mistresses

1. idiomaticSomething which has both significant positive and negative aspects.

   Even if you can’t afford a new one, the cruel mistress of depreciation will soon have her way with the Stinger and that’s very good news.

   2017 January 28, Chris Okula, “The Kia Stinger Will Be One Hell Of A Used Car”, in Shifting Lanes, archived from the original on 26 Jan 2021

   1 more example

   For bandleaders, society can be a cruel mistress. At debutante parties they receive compliments but not calling cards, at charity balls they take their breaks with their players instead of their patrons […]

   1965 December 17, “Snow Job”, in Time Magazine

   Synonyms: fickle mistress, harsh mistress