[Hoshino Ryuichi] Hitozuma Roshutsu Choukyou ~Nazo no Kyouhakusha~ EP 4 [leth]

A married woman's exhibitionist training escalates when the masked blackmailer's orders follow her home—her husband notices how unusually aggressive she's become in bed, but she can't explain why. Dispatched to an open-air bath and ordered to strip before anyone catches her, the big-breasted wife ends up on all fours in thigh-high stockings, a mechanical device pumping her ass while her gas-masked tormentor watches her squirm. Broken down by the end, she's mewling behind cat ears and begging an unseen audience to look at her lewd appearance, confessing she's a slut who cums hardest when fucked outdoors.