Tommy takes Rachel, you take Claire.

"Oh my god, you can't be fucking serious! No way!" Rachel looks between the two of you in desperation. "No. This has gone too far! Please! I'll call my friends over, you can..."

"Shut up!" Tommy snaps at her. "I've wanted you for years. I can do whatever I want to you right now, and you think I'm gonna settle for some other bitch? Get over here!"

Tommy pushes his erection against Rachel's closed lips. It takes a few slaps to her face before she opens up. Tommy takes his time taunting her, slapping his cock against her tongue and laughing as she gags each time. Rachel even seems to be having trouble with the dribble of pre-cum left in her mouth each time he does so. Tommy finally grabs her head and unceremoniously pushes his cock into her mouth and against her inner cheek, making it bulge obscenely. She blubs and splutters pathetically around his dick, eyes clenches shut and hands slapping at his thighs.

As much as Tommy seems to enjoy her struggling, the slapping is clearly distracting him. He grabs her tight waist and re-positions her so her head is dangling over the side of the bed. Rachel tries to squirm out of the position, but is too busy gagging and spitting out pre-cum and gag juice to overpower him. As Tommy positions his cock and slides it deep into her mouth, she goes berserk. Her body spasms like crazy, legs kicking the air and hands pushing at him.

As you carry on watching Tommy have his way with your little sister, you casually grab hold of Claire's shoulders and **** her down onto her knees. "What do you think you're doing, David?!" she screeches. "You can't ju...GLUGH! GACK!" You silence her protests as you shove your filthy erection into her mouth, smearing her lipstick across her face.

You look down at Claire's angry face. "Look, we can do this the easy way..." You gesture at Tommy and Rachel. "Or the fun way. Up to you."

Claire's frown quickly turns to worried surprise, and she shoots a glance towards the bed. She looks back at you pleadingly. You return her plea with a blank stare, and she soon gets the picture. She reaches up and starts to stroke the base of your cock, flicking her tongue around the tip. You let her get on with her blowjob and continue to watch the show.

Tommy has clenched his legs around Rachel's head, thrusting forward and pinning her skull firmly between his crotch and the wooden edge of the bed frame. He grabs both her wrists in his fists and pins them to the bed. Rachel thrashes in vain as he slides himself into her throat. The more she struggles, the more it excites Tommy, and the harder he fucks her. Before long, he's hammering into her throat, treating her super-sensitive, tight passage as though it were a loose pussy. The sounds of her constant gagging fill the room. In all your days of watching porn, you've never heard a girl sound so nauseous, nor seen her face used so brutally. You're not sure whether to be disgusted or turned on as you watch her spluttering in discomfort, gag-slime and pre-cum spewing out of her lips and nostrils to coat her already glazed face.

Eventually the sounds get quieter as Rachel's lungs run out of air. Her upturned face has already turned crimson with the strain of being upside down, and constantly retching. Unable to either draw breath or expel the fleshy obstruction, she clenches her tear-filled eyes shut as her chest silently heaves in vain. Her knuckles go white as she clenches her bed-sheets tightly, enduring the rough pounding she's taking.

Meanwhile, Claire has stopped sucking on you, and idly strokes your slimy cock as she watches the scene unfold. She looks up at you. "David! Are you going to just let him treat her like that? This is too much! She's your sister, for god's sake. Do something!"

So she's finally showing some concern for Rachel, eh?

"You want the same treatment?" you ask her. Her eyes go wide in fear, and she quickly shakes her head.

"Then do your job," you say, pulling her head back towards you. "I didn't say you could stop." She needs no further encouragement, and dutifully begins licking and sucking the first few inches of your erection, staring up at you submissively to gauge your reaction. She looks keen to please you now that she knows what the alternative is for her. It's no surprise that she cares more about her own well being than her youngest step-daughter's. Claire and Rachel never really got along. That, and Claire always was a self-obsessed bitch. You don't think you'll have to do much more than hint at using her roughly in order to get her to fall in line.

It turns out your step mom actually gives pretty good head when she's suitably motivated. She's ticking all the boxes; long slow licks from base to tip, flicking her talented tongue around the head of your cock before sucking what she can into her warm, wet orifice. All the while her eyes are flicking between you and Rachel, obviously worried about what will happen if she doesn't please you enough. You're fairly happy with her efforts, but decide you want to see how far you can make her take things on her own.

"Is that the best you can do?" you ask her, trying to look as unimpressed as you can.

Claire stops sucking on you for a second, her face showing a mixture of fear and disappointment. "I, um... why? You don't like this?" she answers, giving you a coy look before giving your cock a wet kiss. She lifts your erection and nuzzles her face underneath it, letting the trickle of pre-cum drip into her hair as she licks your balls. It's obviously all for show, but she could have fooled you if she wasn't constantly shooting nervous glances across the room.

"It's okay, I guess," you sigh, trying not to smile. "But I want more."

Claire looks up at you, all fake smiles. "Um. What do you want me to do?" she asks.

You look at Tommy, still brutalizing Rachel's throat. Then back down to your step mom. "What do you think I want?"

Claire hesitates.

"Fine. I'll do it myself" you say, reaching out to grab her head.

"NO! WAIT!" Claire shouts. She gives you another of her shining, fake smiles. "I'll make it good for you. I promise! Just... just let me do it, okay? Please?"

You shrug and gesture to her to get on with it. She takes a few deep breaths and takes you into her mouth, sliding her lips down your wet cock until she reaches her limit. Then, looking up at you submissively, she grabs your ass and pulls you a little further into her mouth. She gags, but holds her position, eyes starting to tear up. After a few seconds she pulls her head away, but keeps the head of your cock in her mouth, swirling her tongue around it before swallowing the mouthful of gag slime and pre-ejaculate. She looks up at you for approval. You offer her none.

However, you also show no signs of stopping her as she starts bobbing her head down a second time. You reach back and casually let her hair down. Then you twist your fingers into her hair until you have a tight grip on the back of her skull. You're honestly quite content to let her do most of the work, but every now and then you pull her an extra inch into you to remind her just who's in charge.

Meanwhile, Tommy's thrusts have been getting shallower and more erratic as he nears his own orgasm. Finally he grabs Rachel's neck in both hands, and grinds her head hard against the bed as he roars in pleasure. You look on in disgusted arousal as his cum spews out of your little sister's nose. It quickly slides down her face. Rachel's eyes bug open in shock - then quickly close again as cum flows into them. She blinks and tries to twist her head out of Tommy's grip as his cum continues it's journey across her forehead to hang in pearly strands from her hair.

Tommy isn't finished with his new toy yet, however. He grinds himself harder into her face, groaning in pleasure. He reaches down and holds her nose shut with one hand, the other gently squeezing her bulging neck. With nowhere else for it to go, Tommy's cum is **** down her throat. Rachel's body spasms violently, trying desperately to repel the unwanted liquid. Her hands slap uselessly at his arms.

Rachel's resistance is pretty feeble by this point. Tommy brutally thrusts a few times as he continues his considerable orgasm - years of pent-up sexual frustration finally being unleashed at your little sister's expense. Her eyes roll back until the whites show, and with a few final shudders, her body goes limp. Tommy holds her head in place, and finishes pumping the rest of his cum into her unresistant body.

He lets go of your thoroughly abused younger sibling, and steps backwards, his thick cock sliding out of her cum-packed orifice. You watch with some concern - but mostly curiosity - as Rachel's petite teenage body hangs limply over the side of her bed, cum dribbling from her open mouth to drip from her face into the puddle beneath her. A few seconds pass. Then a few more. Just as you begin to get worried, her chest heaves and she takes a deep, gargling breath. This is immediately followed by a coughing fit like nothing you've seen before, as her super-gag reflex takes over and she tries to breathe, vomit and cough up the cum she just inadvertently inhaled, all at the same time. She flips over onto her belly. Her soggy hair flops down, obscuring her face. You watch as her body heaves, and about half a pint of jizz, pre-cum and thick spittle flows from under her hair to the floor as she expels it from her body.

She pulls herself up onto her knees, and slumps weakly against her headrest. She coughs and splutters as the fluids dribble from her mouth onto her bed-sheets, before retching and starting to gag all over again. You suspect she'll be at it for a while.

A spluttering sound beneath you redirects your attention. You were so enraptured watching Tommy **** your sister, you didn't realise what you were doing to Claire. You've got her head in a tight double grip, and have been grinding your cock deep into the back of her mouth. You're not sure how long for, but tears are streaming down her face leaving trails of black mascara, and she's going a little red. A vein pulses on her temple as she looks up at you submissively, silently pleading with you for mercy. Heart pounding in your chest and lost to the lust, you pull her head into you even harder, and gasp as your cock slips into her throat. She splutters around your 10 inch tool as it slides in to the hilt. You've still got a ways to go before you reach your own orgasm, but already Claire's chin and blouse is dripping with your combined body fluids. Another of her expensive outfits ruined. Perhaps you'll take her shopping once you're done, and get her to buy herself something more suitable for your needs.

Your reverie is broken short by the sound of someone thumping up the stairs.

"Claire? What's going on up there?" your guest calls out. You swear you recognise the voice.

"Are you okay? I could hear... oh my god!"

The door swings open.