Go Find Rachel

You finish off your snack before reaching down and scratching your balls. Your cock begins to stir a little after getting a good look at your step-mom's swaying hips. You think back to throat-fucking Rachel on the couch and stroke yourself back into a painful erection.

"Damn. Well, I know Rachel is 'willing'. Sort of. Close enough. Let's see where she went and get some more of that bitch's throat."
You get up from the table and head back towards Rachel's bedroom. Her door is open and she's facing away from you, going through clothes in her closet. You notice she's also still topless. You sneak up behind her and surprise her by grabbing both her breasts from behind.

"BOOO!"
She jumps at your touch.
"Dammit, David. Stop doing that to me."
You grind your dick against her ass through her shorts.
"Fuck, David, stop it. You already **** my throat on the couch, go find someone else to fuck with."
The thought crosses your mind for a second. You wouldn't mind fucking your step-mom or Mel.
"Sorry, sis. But your throat is just too good. I need it again."
You start tweaking your nipples and she slaps at your hands.
"Fuck no, not that shit again, you were fucking brutal last time."
You let go of her breasts and slide your hands down to the top of her shorts.
"I don't think you understand, Rachel. I take what I want, when I want it. If I want to fuck your throat, I'm gonna do it."
You grab the top of her shorts and yank them down her legs, exposing her sweet ass to your face. You grab both ass cheeks and spread them apart, getting a good look at her puckered asshole and shaved pussy. You stand back up, reach around and slip a finger between the folds of her vagina.
"Then again, I can find another use for you, sis."

You slowly dip your finger into your sister's hot box. She squeals as you penetrate her, but you can already feel her getting wet.
"Ugh, fine, do whatever you want."
She's stopped really resisting you and you reach back up and fondle her breasts again. You lean in and bite her neck lightly.
"Oh, I will."
With that, you pick up Rachel and throw her onto the bed. She screams and bounces on the bed springs. In a flash, you grab her hair and twist her head. She's now laying face down the bed, but with her neck craned up and her mouth level with your cock.
"Open wide, slut!"

She hesitates but opens her mouth anyway. You step forward and the head of your cock enters her warm mouth again. You place one hand on the back for her head and reach the other under her chin. Then you slowly sink yourself all the way into her mouth. You hit the back of her throat and she gags. You back off a bit and thrust in again. Her throat still resists you.
"Come on, sis. I know you can take it. Do I need to flip you over and fuck your mouth that way again?"

She quickly shakes her head and reaches out to grab your ass, pulling you into her mouth. This time, you bump the back of her throat, she gags, but she keeps urging you onward. With a little more effort, you slip into her throat and push yourself all the way to the hilt.
"FUCK YEAH!"
With a firm grip on her head, you rock your hips back and forth, fucking your sister's willing throat.
"This feels so good sis, you have no idea."
You pick up one of your feet and step onto the bed beside her head. This new angle let's you fuck directly down into her throat instead of just thrusting forward into the bed.
"YES, YES, YES!"
You start pushing your cock deep into her throat and holding it there. After a few seconds, Rachel starts gagging hard on your cock. But you hold yourself in her throat. About 30 seconds go by and you finally relent and slip out of her mouth. She coughs and sputters beneath you. You use this opportunity to slap her in the face with your dick a few times.
"You are such an ass."
You take your hand off her chin and use it to guide your dick back into her mouth. Her brow furrows and you reach under and grab her neck. You can feel yourself pulsing in her throat. You hold yourself in her throat again. She gags and chokes. Spit dribbles out onto your balls and her chin. There's a small puddle forming on the floor beneath you. You rock your hips a little, never leaving her throat. This time, you hold for over 40 seconds. Backing off, Rachel wretches and chokes even more than last time. You grab your cock and line it up again.
"No, please, I can't do that anymore."

You've had enough of her complaining. You cockslap her right across the face. She winces. When she does, you reach down on the floor and find another shirt. You jump on the bed and tie both her hands behind her back again.
"Feisty little one, aren't ya?!"
Once her hands are tied, you get back in front of her.
"Please, no ..."
You reach down and flip her over. Now her head is hanging down off the end of the bed, one of your favorite positions. You grab her neck and squeeze. She whimpers but then opens her mouth and takes you back in. You thrust all the way into her throat and hold it again. She spits and sputters and gags. Her body starts thrashing on the bed, but you hold her down. After about a minute, you finally pull out. She wretches hard again and gasps for breath. You line back up and thrust all the way in to the hilt again.
"YOUR THROAT. AW. SO FUCKING GOOD."
Your grab both her tits and piston in and out of her throat now.
"Damn, so good."

You feel your orgasm quickly approaching.