She forces him to rape his own sister

A/N: It's been a long while.

Kassandra binds Lily in tight rope and then places her in a doggy style position on the bed, ass hanging up and outwards. She force-feeds her a potion, and Lily's face is suddenly flush with heat, her nipples turning erect and her pussy starting to leak like a beer tap.

And then, Kassandra manhandles Valwin and positions his monstrously long schlong at the entrance to Lily's birth canal, and the young boy instantly understands what's coming next.

"No, no, no! Please, not my sister! Don't make me do this to my-"

With a forceful shove and overwhelming strength, Kassandra forces Valwin's penis to pierce Lily's hymen, and the poor girl screams as her virginity is taken. Kassandra is not done, forcing Valwin to push himself deeper inside until he was balls-deep inside her vaginal. Despite the immense lubrication from Lily's state of arousal, her vaginal was still quite tight, and it took a full minute for Lily to acclimatise to this foreign intrusion.

Both Valwin and Lily cried uncontrollably, the poor brother feeling even worse.

"Why... Why my sister...?"

"Because I felt like it," Kassandra said coldly.

Valwin would soon begin thrusting under duress, his penis stretching out the Elf girl's smaller vagina. Despite his feelings, he began to utter moans of pleasure with every motion, her wet juices easing his ingress and egress, and the way her tight folds caressed his exposed pink tip caused him to reach a new high of ecstasy. His voice came out in ragged gasps and high-pitched whines, worsened by Kassandra licking and biting his pointed ears and fingering his ass.

"Ah, no, not there...!" He whined, "Not where I defecate..."

"Too bad, little boy. I'm in control, I get to do what I want."

Before long, Valwin found himself approaching the edge of climax, and managing to master his instincts, he hastily tried to pull out. Kassandra stonewalled him, smacking him in the ass and making him yelp in shock. Unfortunately for him, it proved an adequate distraction, and he ejaculated his semen inside his own sister's womb.

He groaned in agony and pleasure, feeling his own cock unleash more semen with every throb, before he finally collapsed onto his own sister, panting heavily.

Then, horror dawned on his face before it morphed into anguish and guilt, and he turned to the side and cried himself to sleep, repeatedly apologising to his sister under his breath. Lily embraced and soothed him, for whatever good it did.

Kassandra smirked, cleaning herself in the house's bathtub.