18+ Hana to Hebi The Animation

Shizuko, a 26-year-old housewife, is lured into a trap when her stepdaughter is kidnapped by the Kizakura gang. The kidnapping scheme was hatched by an evil CEO whose main goal is to make Shizuko his sex slave. Eventually, she's coerced into performing a bizarre sex show in front of a large audience. They force Shizuko to perform with her stepdaughter. Though she refuses at first, she gradually accepts and decides to roll with the twisted pleasure of it all.

(Source: AniDB)