"You're so mean to your sister."

Carrie's mouth drops. You said it in a playful manner, and you suspect she's taken it in the same way, but you're not 100% sure.

"That's not true." She laughs. "I just gave her the clit rubbing of a lifetime. How am I mean?" She waits for your response, but you have none to give. You're too distracted by the sound of Ella softly gagging on your member. But still she does nothing to pull back as you thrust it into her throat. So Carrie goes on, "When she was in middle school and I stole her bike, that was mean. When she was in high school and I fucked her boyfriend, that was mean."

Cassidy let's out a muffled moan, louder than the ones she's been making so far. She's clearly reacting to what her big sister is telling her.

"It was Dan. He was a jerk anyway... and Gregory." Carrie rolls her eyes as if in anticipation of the big deal that will one day be made of this. In fact Cassidy seems to be trying to raise up her head, but Carrie keeps it shoved in their niece's twat.

"See." you say. "Mean. You're gonna suffocate her."

"You're one to talk" Carrie fires back, gesturing at Ella's petite body as it jerks and convulses around your member. You're not sure why she doesn't relent. It's as if she's been overtaken by a compulsion to gag on your member. But it's certainly not because you're mean.

"She's having a great time." You grab the base of your dick and pull it from Ella's young, soft, lips. "Right?"

After the spittle is done pouring out after it, she answers, "Great... time..." panting heavily.

"Okay fine!" Carrie throws up her hands and immediately, as soon as she ungrasps her sister's brown hair, Cassidy's head flings up, a great mess, covered in her niece's teenaged pussy juice, panting as if she's just surfaced after days underwater. But it's a brief respite from being manhandled by her sister. Suddenly she's being grabbed and thrown onto her back. "I'm gonna be super-nice to Cassidy." Carrie declares and pushes her face between her sister's thighs.

You and Ella watch as Cassidy's face first tenses up, then releases, then her eyes jolt open wide, and the breaths she doesn't have to give start pouring from her mouth. Carrie lifts her head up for a moment. Whatever she's doing down there, it's special. "C'mon. Let's all be nice to Cassidy!" She insists and then re-buries her face.

You and Ella exchange glances. It's unreal. It's all totally fucking unreal.

So you slide over and present your messy cock to Cassidy. Finally. It's her's. You wonder what it taste's like. Some combination of her niece's twat combined with the thick saliva that lives in the back of a girl's throat. Cassidy doesn't seam to mind. She licks it up and down, gazing at it.

Ella slips over to her and slides her lips around her aunt's hard nipple.

You run your fingers through Cassidy's hair. It's so very sweaty. You're glad you have this moment to make eye-contact and smile at her. After weeks of naughty texting, you feel like you've really built up a relationship. A fucked up relationship, but something.

"What's it like having your sister eat you out?" You ask.

Cassidy's pulls her tongue off your cock reluctantly. Her lip quivers. "It's... she's making me explode. I'm never going to stop exploding."

Well, you suppose, that's an answer. And indicative that whatever is happening here can't be undone. Whatever normal life is being exploded doesn't get pieced back together. There's a sense in the room that a threshold has been crossed, and what's on the other side is mysterious and maybe a little scary and a lot taboo. And this is just the beginning.

You shout for your girlfriend. "Carrie!"

She pulls her head up. "Can't you see I'm trying to give my sister the greatest orgasm of her life?"

You smile. "When you were stealing her bike, did you ever think you'd say those words?"

Carrie shrugs. "Maybe. When it comes to sex, I never think in terms of "never.'" And she buries her head back in Cassidy's wet twat. But then suddenly pulls back out. "Except, my sister is never going to get over this climax." A smirk and then back to it.

Cassidy makes eye contact with you again. She doesn't know what face to make.

"She likes encouragement." You tell her, giving her information on her sister, surely she never expected to have.

And taking a deep breath Cassidy softly eeks out some words. "Eat... eat me... eat me sis."

"Do it Aunt Carrie!" Ella chimes in, more energetic and loudly. "Make Aunt Cassidy cum all over."

You chime in. "Be a slut for your sister! Give her an orgasm she doesn't deserve!"

"Yessss..." Cassidy is getting louder. "I don't des... I don... oh god.... oh fffffFFFFFFUUUUUCCKKKKK!" Cassidy's whole body tenses and shakes and tenses and shakes. Ella screams with delight at seeing it happen inches from her own naked form.

And then Cassidy goes totally limp, so completely drained, she drools as she lies flat on the floor. She's done, eyes open, but completely sexually KO'd.

Carrie, her face a mess of her sister's juices, turns her attention to her niece. "You next? Wanna cum like you've never cum before?"

Ella looks at her then at you, then back at her. "I mean..." and promptly lies down on her back. Her aunt jumps over, getting in position to 69 her.

"How many pussies have you eaten?" Carrie asks of her young niece. Ella hesitates. But Carrie isn't having it. "Oh fuck that, don't be shy."

"Seven" Ella answers with a big smile.

"You little slut." Cassie teases.

"I am not!" Ella chirps.

"Okay, you big slut!" Cassie teases some more as she spreads her neice's freckled cunt and spits into it. "How many cocks have you sucked?"

"Sevennnnn" Ella snips.

"Liar!" Carrie starts to lick her niece's thighs.

"nnnnnteen. There. Ok?" the teenager retorts.

"Including his?"

"Eighteen! God!" Ella suddenly feels pleasure start to wrap around her body. You can see it in her face. "Gggggodd!"

And before finally delving in to dine out on her niece's fresh twat, Carrie fires, "well you want to know what it's like to live on your own and go to college? We're gonna double those numbers this weekend. You can start by adding your aunt's sweaty cunt to the list."

And just as she lowers her head into Ella's crotch, her brown hair draping over the girl's pale thighs, Ella leans up and slides her pink tongue into her aunt's slit.

The girls moan as they eat into each other. And you decide your cock, on the verge of bursting, needs something to do.