Zoe likes to "watch"

The robed girl plopped herself down on a cushioned chair just opposite of Kim's face. Kim could see no sympathy in her eyes as Nathan gripped his hardening cock in his hand, and began to tease at Kim's backdoor.

Kim wanted to shout or run, or do something, but she knew now what she was in for and why she had to bear it. She grit her teeth as Nathan leaned against her until...

"Ahh!" Kim cried out as he shoved his violating member into her tight ass. His cock was thick and painful as he **** it deeper into her. Her scream turned into an unwanted groan of pleasure as he began to pump his way in and out of her.

Nathan roughly grabbed onto Kim's arms, pulling them back and using them as handlebars as he fucked her over the desk. Her torso was pulled up some, and Zoe got a good view of Kim's heaving breasts as they shook with every thrust.

Kim noticed that her eyes had been closed. When she opened them, she noticed that Zoe had opened her robe. She was reclining, practically naked. Her black pubic hair still wet from the shower, or... something else. The dark-haired woman bit her lip as she rubbed her clit, watching intently as her brother fucked Kim from behind.

Kim felt so used, humiliated, degraded as Nathan continued to violently fuck her hole. Yet, she felt a strange, unwanted pleasure from it. She wanted to resist this, to reject this feeling of arousal at being used. But it stuck to her like a bad memory, one she couldn't forget. She felt herself moaning despite the situation. Did she actually want Nathan's cock?

She would have to answer that question later, as she felt his thrusts quickening, until. Nathan grunted with satisfaction as he plunged his cock to the hilt inside of her ass. She felt a warm gushing deep inside of her as he filled her with his cum. Kim groaned as she felt his filthy seed entering her. That's all she was to this family, a cum depository.

In front of her, she heard a softer moan, as she watched Zoe cum soon after. She had begun to grope on of her luscious tits as Kim was getting fucked. The rich girl shook with the orgasm, her wet cunt moistening her fingers as it weakly squirted onto the bathrobe.

Nathan pulled his cock out of her, and began to wipe it off with tissues from on the desk. "Do you want her next?" He asked to his sister.

Zoe looked over the now cum-filled Kim. "Hmm, why not?" She answered, much to Kim's chagrin. "I suppose I haven't really spent much time with her."

Nathan grunted. "Have fun then." He said before exiting the office, leaving Kim alone with his deeply amorous sister.