A pickpocket living in a small hut comes across a woman lying on the roadside. It would seem the woman is a "Domesticated Succubus" that has been modified so that she can be of no harm to any human... That is, a very valuable sex sl*ve.
Your butler. Beauty admired by everyone for her stoic complexion and slender figure befitting a butler. Sexy, feminine side shows in all the good places. True nature becomes overly apparent as she takes it upon herself to relieve you sexually.
An S-class adventurer (you) gets violated by two legendary succubi and their two clones (4 slutty succubi in total). Experience the "Square Illusion" of receiving attention from all 4 directions at the same time! You are... just food to them...