Sister, Sister.

Both of your girlfriends gasp and squirm when the vibes turn on. You quickly turn them off and on a few more times. You leave both your girlfriends panting and staring at you lustily. You look from your panting girlfriends on their chairs to the pile of girlfriends’ sisters still coming down from orgasmic highs on the bed. You grin and pulse the vibrators again, watching both your girlfriends jump against the cuffs.

“I like this game.” you chuckle as you survey Andrea and Casey still breathing deeply, “What next? Should I fuck little Casey? Or should Andrea get it again?”

You pulse the vibes again twice. Brittany and Katie squirm. They’re both wound up from being tied and unable to stop you having your way with their sisters.

“Casey.” Brittany moans, you reward the big woman by turning her vibe on and lowering the intensity. You watch as she grinds her round hips against the chair, “Fuck Casey like you did me this morning at work.”

You grin at your busty girlfriend, she’d sent you a text to meet her on the roof at work, she’d offered you her big round ass. You’d plowed the globe shaped ass while she was bent over the safety railing looking over the city. She’d swallowed your load for easy clean up so you could go back to work. You smile at the memory, while grabbing her little sister’s ponytail and guiding her to her hands and knees facing Brittany on the bed. The tiny blonde is still breathing hard but looks at you over her shoulder with a devilish smile. She’s on her hands and knees facing her sister, her thin limbs holding her up with a small arch in her back. You gently spank her small ass and she squeaks. You feel Andrea start to crawl around on the bed, you just survey the tiny blond presenting herself to you. Suddenly the stacked brunette is behind you, her breath is hot in your ear, her hands are slowly stroking you again, spreading lube all over your impossibly hard cock.

“Fuck that little ass.” Andrea breathes, “Make the tiny bitch scream so you can do the same to me.”

Andrea nibbles your ear in much the same way Katie always does before pushing you forward against Casey’s tiny body. Her rosebud is in full view between her cheeks, you watch as Andrea’s elegant arms reach around your waist to spread a little lube on the blonde’s tight ass. Casey coos and wiggles her hips against the long elegant fingers that are preparing her. Katie and Brittany are panting and grinding against the chairs as Andrea prepares both you and Casey. Andrea’s fingers slip gently inside Casey’s ass, and her other hand lazily strokes your cock, making sure you stay hard, but there is no danger of that given what is happening around you. This goes on for a few minutes before Andrea quietly whispers to you, “She’s ready.” And you slowly start to push forward, Casey’s ass resisting your tip as the slim blonde tries to relax.

“Relax Casey,” Brittany pants to her sister, “Let my man’s cock inside you.”

“Fuck me.” Casey moans, “It’s so fucking big.”

“She’s tighter than anything I’ve ever had!” You grunt as a few more inches of your cock disappear into the tiny blonde.

“Too big.” Casey moans.

“Almost halfway in.” Andrea moans over your shoulder. The thick brunette is fiddling herself on her knees behind you. Her other hand playing with your balls as you push further inside Casey. You slowly fill the right ass and your balls swing against her hot slit, Andrea’s hand drops away.

“Is it in?” Casey grunts, her eyes are watering, her face and chest are flushed red, her thin arms are shaking trying to hold herself up.

“All. The. Way.” you groan, gently pushing against her with each word.

“Fuck.” Casey groans, her arms fail her and she collapses against the bed, the rest of her body held up by your cock, and your hands on her hips. Andrea is grinding her smooth body against your back, you delight in feeling the heavy DDs pressing against you while your cock is being milked by the tightest ass you’ve ever been in. Andrea slides her body down your back and ends up on her hands and knees behind you, her head at ass level. She buries her face in your ass again and starts licking with unrestrained passion, she’s giving you more sensation while you’re letting Casey get used to your invading rod.

“Fuck Katie, why don’t you rim like your sister? She’s fucking amazing.” You groan and switch Katie’s vibe back on as Andrea begins lewdly slurping your ass. Katie groans and grinds her hips, her athletic body tensing up again as she strains against the cuffs.

“Anything for you baby.” the birthday girl pants, “Uncuff me and I’ll slurp it better than that bitch. Fuuuuuuuck!” Katie’s voice rises to a wail as she climaxes again from the vibe.

“Didn’t take long to get her begging to get out.” you grunt, “Just fuck her sister And she’ll do anything. Not yet Katie.”

Katie writhes against the still running vibe. Brittany grunts against hers too. Andrea pulls away with one last loud slurp. Casey lifts her upper body off the bed on shaking thin arms and looks from her busty sister to you over her shoulder.

“Fuck me stud.” Casey groans while grinding her ass against you, “Pull my hair, **** me if you want, and pound my tight little ass.”

You don’t need much more of an invitation, you’re so charged up from the events taking place, you slowly start thrusting in Casey’s tight ass. The blonde moans and groans as she rocks forward and backward from your slow thrusts. You let go of her hips and let her bounce off you a few times before reaching up and grabbing her blonde ponytail and pulling her back against you. You stop thrusting and let Casey pull away before pulling her back by her hair.

“Fuck it’s so big Britt.” Casey moans, “Your boyfriend is splitting my ass with his monster cock.”

“Fucking pound her stud.” Brittany moans, “Tear my little sister up from inside.”

You pull Casey back by her hair a few more times, letting the blonde impale her ass on you. You let go of her hair and run your hands up her smooth back and over her bony shoulders. You start to thrust a little faster when your hands wrap around Casey’s neck, you give her a little squeeze and she groans.

“Yes. Ch-oke me and po-und me.” Casey gasps.

You start thrusting even faster, your balls swinging freely and slapping against Casey’s tiny slit. You watch your girlfriends watch you fuck Casey’s ass harder and harder. Suddenly you feel a tongue swiping at your swinging balls. You look back over your shoulder and see Andrea on her back, her head between your legs, her heavy tits sliding off the sides of her chest, curvy thighs open and one hand between her legs fiddling herself, the other grabbing one of her soft tits.

“Good girl.” you grunt while pounding Casey even harder.

“Fuck me it hurts but don’t you dare fucking stop.” Casey wails, “Pound my tiny ass and **** me. Pound me into submission in front of my fat assed sister. Make me your newest fucking slut.”

Casey is rapidly losing control against your pounding cock and squeezing hands, the blonde’s thin body is tense as she tries to hang on. You watch Brittany and Katie writhe and grind. You pound Casey through another set of climaxes from your girlfriends, and you feel tiny Casey getting closer and closer, you look back and watch Andrea push herself to the edge and over, her stacked body going limp on the bed. Casey’s moans rise to an unintelligible wail as you pound her ever harder, her tiny body absorbing the furious pounding, her eyes focus again on Brittany.

“Oh fuck I’m about to cum from this giant dick in my ass. It feels so fucking good!” Casey manages to scream out, “I fucking submit! Use me like a fucking toy. I submit! I submit! I suuuuuubmit. Fuck me like a toy and throw me away!”

You **** Casey again while pounding her hard from behind, Brittany and Katie both cum again. Casey’s body starts shaking uncontrollably and her moans stop as everything tenses and she starts to climax hard.

“Yes! I’m cumming!” she screams and her ass spasms around your thick cock, “Fucking cumming. Throw me away. I’m a toy!”

Casey continues wailing as you slam through her climax, then you give the tiny blonde what she wants. You pick her up from the bed while still thrust deep inside her and throw her over Andrea onto the bed. Your cock slips from her ass as the tiny blonde cums again while flying through the air, her thin limbs flop around as she lands in a heap near the head of the bed, panting and babbling incoherently. You watch both your girlfriends cum again against their vibes.

“You fucking destroyed her.” Katie pants.

“Used her like a fucking toy.” Brittany breathes.

“All for you.” you say grinning at them, “Slutty girlfriends and slutty sisters.”

“I want to see you cum baby.” Katie grunts while grinding herself toward another climax.

“Make slutty sister suck my little bitch sisters ass of your glorious cock!” Brittany shouts as she climaxes again herself.

You lay down and open your legs so your girlfriends can see you heavy cock and balls, and roll Andrea on top of you, her head facing down. The stacked brunette gets the idea quickly and takes you into her mouth and starts quickly bobbing up and down. Andrea is putting on a blowjob clinic as this point. Her tongue is swirling and dancing, her hands reached around and playing with your balls, her throat squeezing you as she gags.

“Fuck her fucking face!” Katie screams, as a double climax washes over her, “Fuck that bitches fucking face!”

Andrea looks at you and winks before holding her head still, you start thrusting up at a fast face. You tip slams against Andrea’s throat with you loud *GLHK GLHK GLHK* sounds. Katie watches you and her whole body goes tense yet again, and several more multiple climaxes race through your girlfriends body. Katie’s eyes start to close and she struggles to stay focused. You look to Brittany and she’s mumbling to herself as she climaxes again and again. Your two girlfriends are losing all control. You get close as well in Andreas throat, suddenly the brunette goes rigid too and then slack. Her head rolls to one side, your cock in her cheek. You push her head back and she starts lazily sucking you again. You grab her ponytail and start using her throat like a fleshlight, desperately trying to get off. Andrea seems to come to and starts bobbing again. Your balls twitch and dance as Andrea closes her lips around your base and locks eyes with Katie. You groan as you release your load into Andrea’s silky wet mouth. You pump 9 or 10 shots into the sisters mouth. She coughs and some spills out. She turns to Katie and shows your massive load in her mouth before swallowing it all, and showing her sister the evidence. You’re in your own orgasm haze as Andrea licks up what she spilled out and crawls to Casey. Andrea and Casey sloppily make out as the brunette transfers your load to the blonde. Casey sits up and shows Brittany the load in her mouth before also swallowing it and showing her empty mouth as proof. The thin blond and healthy brunette slump together and cuddle.

“He’s delicious.” Andrea mumbles.

“Sure is.” Casey agrees contentedly, “That was amazing.”

“Holy shit.” you groan, and grab the remotes and end the vibing of your girlfriends.

“Good birthday?” Brittany pants to Katie, her eyes unfocused and heavily lidded.

“Fucking incredible.” Katie whispers, “I came so many times and never got touched. The hottest part was watching my man use my sister’s throat.”

“And when he broke my sister’s ass.” Brittany agrees, “Bitches leave!” Brittany finishes with a laugh.

“They knew they were just getting fucked and going home.” Brittany giggles when she sees your confused look.

“I had a great time stud.” Andrea says, kissing your cheek and rising from the bed, “See you at Christmas.”

And with that the busty version of Katie disappears to the hallway outside your bedroom, the next time you see her will be at Christmas.

“You broke me. But don’t break my sister.” Casey giggles, kissing your other cheek, “I loved you using me. See you later.”

The tiny blonde disappears as well. You’re left sprawled on your back with your two girlfriends handcuffed to chairs.

“Best birthday ever.” Katie grins, her head hanging slack and her breathing still heavy, “Countless orgasms.”

“I liked mine.” you kid.

“I liked both.” Brittany giggles tiredly, “Gonna let us loose or what?”

“You’re the present giver, I thought this was part of it. You’re wrapped so well.” you retort, and pulse Brittany’s vibe again. The big brunette gasps and writhes.

“Please stop.” she gasps, “I’m so sensitive.”

“Looks like a present to me.” you jab at Brittany.

“You greedy bastard.” Brittany says with mock indignation, “Getting to ogle a party full of hot bitches, flirt with a gang of fitness bunnies, toy with your beautiful girlfriends and not to mention fuck the shit out of two hot willing SISTERS of your girlfriends wasn’t present enough for you?”

You all three break out into uncontrollable laughter at that. She’s right, this feels as much like a present for you as it was for Katie. You struggle to your feet and cross to the chairs. You’re a bit shaky on your feet after Andrea’s skilled mouth **** your load out. You unlatch Katie’s wrists first, followed by her ankles, your girlfriend slumps in the chair. You undo the cuffs in Brittany and she shakily rises to her feet as well.

“Smoke and a drink?” you offer.

“I’m gonna need help walking.” Katie responds, “my legs are jelly.”

You pick Katie up in your arms and carry her downstairs to the living room. Brittany grabs the smokes and pours glasses of whiskey for the three of you. You walk into the balcony stark naked and carrying Katie. You deposit her in the chair and Brittany offers a smoke and her drink. You take one of each as well, you all light up and toast with the whiskey.

“To the best birthday ever.” Katie giggles. Brittany leans over the railing, her round ass up in the air and her huge tits swinging into the courtyard.

“We need to move out of town so we can go farther outside naked.” Brittany remarks quietly.

“Or we could go camping?” Katie suggests, “My friends do a mountain retreat every couple months. We could join them.”

You mull this over in your mind. Being outside naked is kind of freeing, but you wonder about the friends Katie mentioned.

“Which friends?” you ask your girlfriend. She looks at you and winks and downs her whiskey.

“My horny gym friends.”

“They’re trouble.” Brittany says.

“True.” you agree.