Susie and Isabella

1.

Susie pushed the door open with a quiet sniffle, her shoulders slumped under the weight of the afternoon’s humiliation. Her head throbbed in time with her heartbeat, the world tilting slightly as fresh waves of disappointment crashed over her again and again. Ben’s cruel words echoed relentlessly in her mind, each repetition stinging sharper than the last.

“I’ve never met anyone as frigid as you.”

Frigid. The word burned like acid. She wasn’t frigid. She wanted him — God, how desperately her body had ached for him every time his hands wandered over her skin. Heat would bloom low in her belly, her nipples would tighten, and her pussy would grow slick with need. But something always stopped her. She needed to feel truly owned, completely taken, dominated in a way that left no room for hesitation. Ben only wanted a quick fuck. She wanted to be claimed.

Still wiping at the corners of her eyes, Susie shrugged out of her light jacket and kicked off her shoes. The house was supposed to be empty. Isabella should have been at school, just like her. But their last class had been cancelled, and now here she was — raw, frustrated, and aching in ways she didn’t want to examine too closely.

Then she heard it.

A faint, breathy sound drifted down the hallway. Susie froze, one hand still on her jacket. Silence followed. She exhaled slowly, trying to convince herself it was nothing. But then it came again — softer, yet unmistakable. A low, feminine moan.

Her pulse quickened. Isabella? No... that couldn’t be. Her sister was the responsible one, the good girl. Susie took a hesitant step toward Isabella’s bedroom door, her bare feet silent on the wooden floor. The sounds grew clearer with every step. Wet. Rhythmic. Filled with raw pleasure.

Susie’s hand trembled as it found the doorframe. The door was slightly ajar — just enough for the obscene symphony to spill out into the hallway. Isabella was moaning now, constant and shameless, in a slow, filthy rhythm that made Susie’s cheeks burn with embarrassment.

Go to your room. Right now. This is none of your business.

But her feet wouldn’t obey. Instead, her fingers slowly pushed the door open another inch. Just enough to see.

The first thing she saw was her sister’s face — flushed, eyes half-lidded, mouth open in ecstasy. Isabella was on all fours on the floor like an animal in heat, her school skirt pushed up around her waist, panties nowhere to be seen. Her back was arched deeply, pushing her ass higher into the air.

And behind her was Duke.

Duke. Their massive family dog, a Rottweiler, the friendliest, most peaceful lap dog in the world. Susie blinked in confusion, her pulse suddenly hammering in her ears. What the hell was going on in there?

Without even noticing it, Susie’s fingers slowly pushed the door open a little further. Her sister was kneeling on the floor, head lowered, soft cries of pleasure slipping from her lips without restraint now. Duke was behind her, pressed tightly against Isabella’s back, pumping Isabella roughly..

Susie’s eyes widened. No. There was no way. No way her sister was fucking with the dog.

“Oh God, Duke... yes... faster...” Isabella gasped, her voice dripping with desperate need.

Susie’s stomach dropped. Her mind refused to process what she was seeing. Duke — their family dog— was mounted on her sister’s back, his powerful, muscular body covering Isabella completely. His hips were slamming forward with brutal, animalistic force, driving his thick, veined cock deep into her sister’s pussy with wet, obscene sounds that filled the room.

Isabella was taking him. Willingly. Greedily.

“That’s it, Duke... pump my pussy, good boy!” Isabella moaned loudly, pushing back against the dog’s savage thrusts. “Oh yes, don’t stop... stretch your bitch’s tight, wet cunt!”

Susie couldn’t breathe. She knew she should run. She should slam the door and pretend she never saw this. But her legs were rooted in place, her eyes locked on the horrifying, mesmerizing sight. Duke’s massive body moved with raw power, each thrust forcing Isabella forward slightly on the floor. The wet slapping of his heavy balls against her sister’s clit, the slick sounds of her drenched pussy being stretched wide open — it was all too much.

Susie felt a shameful heat bloom between her own thighs. Her nipples hardened painfully against her bra. No. This is wrong. This is sick. Yet she couldn’t tear her gaze away, she simply watched, frozen, as her sister moaned and enjoyed Duke's dick.

Duke’s pace quickened, becoming even more violent. Low, guttural growls rumbled from his chest as he claimed Isabella like a dog claiming his bitch in heat. Isabella’s moans turned into broken cries of pleasure.

“Oh yes, that’s it Duke... fill me up with your hot cum! Breed your bitch!” she begged, voice cracking. “Let it all in me... I want to feel you flooding my womb!”

Susie wanted to run. She really did. But her legs wouldn’t move. She just stood there, frozen in place, watching the dog fuck Isabella hard as if she were another dog, while her sister’s cries echoed through the room.

The dog’s movements grew heavier, more forceful. Susie watched in stunned horror as the thick, swollen knot at the base of Duke’s enormous dick began pressing against Isabella’s stretched entrance. It was massive — far too big for any woman. But Isabella only pushed back harder, desperate for it.

“Push that knot into me, Duke! I’m your bitch... force it in! Knot your family whore!” Isabella cried out, her body trembling with need.

With one powerful, savage thrust the huge knot finally popped inside. Isabella let out a loud, broken scream of pure ecstasy, her whole body shaking violently as the monster’s knot locked them together. Her eyes flew open in that exact moment — and locked directly onto Susie’s wide, horrified gaze.

For a single, frozen second, time stopped.

Fear, shock, and something darker flashed across Isabella’s flushed, sweat-covered face. She was still impaled on the dog’s throbbing knot, looking every bit like a dirty, well-fucked family slut.

“Susie...” Isabella whispered hoarsely, voice shaky and breathless. “This isn’t... it’s not what you think. Please... just let me explain...”

Susie’s stomach twisted violently. Shame, disgust, and a confusing rush of unwanted heat flooded through her. Her vision blurred with tears. She couldn’t speak. Couldn’t think.

At last her legs obeyed. She turned sharply and ran down the hallway, her heart pounding wildly in her chest. A second later, her bedroom door slammed shut with such force that the walls shook.

Want to know what happens next? The story continues in the next chapter!