Sister Mari and brother Yuuta are the children of my late wife's sister, who died in an accident along with her husband, leaving the two orphans in my care. My wife was a masochist, and as a sadist, I trained her to be my perfect love slave. After she passed away from illness, the three of us began living together. That's when I discovered the incestuous relationship developing between the siblings. Though they aren't blood-related, they are still my wife's family—and yet, a dark voice inside me whispered: "Make them happy. They're sister and brother, indulging in forbidden pleasure, both born masochists. You, as a sadist, must dominate them and lead them to happiness."
I began training them. I fucked Mari while Yuuta watched, and she cried out in ecstasy. "Don't look... Yuuta..." she pleaded, even as her pussy clenched tightly around my cock. Yuuta's own penis stood erect, throbbing and dripping pre-cum as he stared. "Don't look? You're squeezing my cock with your pussy, you slut. Yuuta, tell me—your sister's pussy feels amazing, doesn't it? You've fucked her countless times with that hard cock of yours, haven't you?"
"...Yes, sir."
"Mari, Yuuta—you understand, right? From now on, you're forbidden from having sex without my permission. Mari's pussy belongs to me. As for you, Yuuta, I'll introduce you to a new woman. A cute, obedient Dutch wife."
Excited by my own words, I came deep inside Mari. Then, while she rode my face, I forced Yuuta to lick my cum mixed with her juices clean from her body. "Look, Mari, clean the cock you've dirtied with your own pussy juices." Following the blowjob etiquette I'd drilled into her, Mari sucked every drop from the base of my shaft to the deepest part of my balls, meticulously cleaning my groin and scrotum without using her hands. "Yuuta, how does your sister's pussy taste mixed with my cum? But don't just lick—make her climax. Lick her with the intention of pleasing her."
"Yes, sir!"
"Mari, Yuuta is cleaning your pussy with his tongue. Now, Yuuta, jerk off while you lick my cock, and make your sister cum again."
My revitalized cock plunged into Mari's throat, and just as ordered, she reached a powerful orgasm. As my sex slaves, both sister and brother seem truly happy. I will continue to raise them deeper into this incestuous hell, forging them into perfect, obedient masochists.