It had been nearly two days since Leif had last cum. He was beginning to feel pent up, and it showed in his frustrated expression and the perpetually half-hard bulge in his shorts that constantly soaked through and required replacing. The fact that he was 6’3” and had the build of a dedicated athlete meant he could easily get a quick lay on campus if he wanted to, but that sounded like so much work. He didn’t feel like impressing anyone or sifting through hookup sites for easy sex. His long tail dragged back and forth over the sheets of his bed, and his dark black claws clicked against the frame.  His polished, green scales soaked up the afternoon sunlight while his golden eyes roamed over the screen of his tablet.
Leif was shopping online for a new set of weights. He had been feeling good about his current record of 415 pounds, but he knew he could push himself further. As the male allosaurus imagined the gains he’d soon be showing off around campus, he started wondering if that pretty shark woman at the gym would notice. He bit his lip and opened a new tab, quickly finding the video he’d been using to masturbate to for the last few days. Before he could start enjoying himself though, the door slammed shut hard enough that Leif felt the pressure change in the apartment. He quickly closed the window and hoped his dick wouldn’t drench this pair of shorts, too. His sister and roommate, Rose, was supposed to be gone for the rest of the night on a date, but it looked like that wasn’t happening. Rose stomped into the room and hissed through her teeth. Her pink face had flushed entirely red with rage.


        “Stupid fucking men!” She started pacing back and forth in front of the bed. Leif watched her tail with growing concern, knowing she was prone to knocking items off dressers and tables without realizing it. She pulled her shirt up and over her head, flinging it into a corner with a pile of Leif’s own dirty laundry. “I am never, and I mean ever, going to date a man again! They’re all disgusting, pathetic, selfish pricks!”


        “I warned you he was trash.” Leif scrolled further down the shop page, pretending to be disinterested as he watched her out of his peripherals. Her curves were burned off a long time ago, but he’d never really cared. Rose’s body was 74 inches of muscle, hide, and bone, and she looked like the killing machine their ancestors had been long ago in the primordial jungles of the late Jurassic period. Personally, Leif wouldn’t have it any other way. He loved his sister just the way she was. 


        “Shut your mouth and let me vent!” She retorted as she stopped to slip her pants down and then step out of them, leaving her in her black, tight-fitting underwear. “He just, he seemed alright! Maybe a little too nice, but normal, you know? And yeah, he’s not the handsomest guy, but I really liked his confidence when he came up and asked me on a date.” She let out a groan and dragged her claws down her face. “But then we get there and he stinks, and he talked all about how he doesn’t get why women never get past the first date with him, and he tried to put his hand on my thigh like right away, and ugggh!!” She punched the air in front of her a few times, clearly picturing her date’s unfortunate face. “I should have fucking maced him. I should have kicked his ass and tossed him in a dumpster. But I didn’t. I tried to give him a second chance, because I’m supposed to be trying to be nicer.” She spit the last word out like it was food she had just realized was spoiled after tasting it. “So what does he do? He fucking starts talking about kids! I don’t want to talk about how our fucking babies will look on the first date!”


        “So what did you do?” Leif sat up a little more and finally set his tablet to the side, actively listening as his sister complained about her misogynistic date. “Do you want me to find him? I’ll make sure he stays away.” Rose sighed and shook her head.


        “No, he won’t be bothering me. I yelled so loud the whole restaurant heard, and I made it clear to everyone he was a creep.” She slipped her shoulders through the loops of her bra and let it fall to the ground, exposing her perky tits. “No, I just need to get fucked so I can calm down. Are you too busy, or can you help me out?” Leif smirked. He wasn’t surprised in the slightest. Rose always needed sex. It was her coping mechanism as well as her favorite pastime. He slipped his shorts down, letting his fat, ridge-covered cock spring up and throb in front of her. All ten inches of green, leathery cockmeat twitched with his pulse. A pearly bead of precum slid from the tip all the way to his weighty, avocado-sized balls.


The twin dinos had been having sex for years. They each knew what the other liked better than anyone else. Convincing their parents to let them get an apartment together for the sake of saving money had been easy enough, and it meant they could fuck whenever they wanted, which was often enough that Leif’s grades suffered slightly. The two were practically inseparable. Now, as Rose found comfort in her brother, the male allosaurus thought briefly how lucky he was to have such an awesome sister, even when she was in a bad mood. Not that he blamed her, her date sounded like a real creep.
        
“You know I’m never too busy for you, nerd.”  he said. Rose rolled her eyes and slipped her thumbs into the waistband of her panties before stepping out of them.  A thick strand of pussy juice clung to the fabric. 


        “Fuck you, at least I’m not getting a C- in fucking BIO 100.” she teased back. She climbed into the bed and bent down to kiss his cockhead, then took it into her hand and sealed her lips around the tip. Leif groaned and put a hand to the back of her head. Her tongue slipped out of her warm mouth and around his shaft, stroking it as she bobbed her head. He felt the lightest graze of her knife-like teeth against his cock, but that only made Leif more excited to feel a hint of danger mixed in with their play.


        “Fuck, Rose, I knew no wimpy political science major was gonna impress you. You need someone who can keep up with you in the gym and in bed.” He slid his hand over the crest of spines running from the middle of her head down to her tail. “Besides, you’re like an 11, he was a 4 at best.” Rose popped the dick out of her mouth and started stroking it while she glared up at Leif. 


        “Can you not give me sex and dating advice while I’m sucking your cock? It’s really taking me out of the mood.” Leif chuckled and shrugged, nodding his agreement.


        “Yeah, sure. You’re just looking to vent, right? You don’t want advice.” Rose nodded and sighed, looking away while she absentmindedly kept rubbing her brother’s cock. It had brought her a lot of happiness throughout her life. It was almost meditative for her now.  The sticky coating on both his cock and her palm made the feel of sliding her hand that much dirtier. She bent down and nuzzled his nuts, taking deep breaths of his masculine scent, making her head buzz.


        “Yeah, that’d be great if you could just…I don’t know, make sexy sounds and say hot things or whatever.” She took her brother back in her mouth and swallowed him down nearly to his balls. Leif groaned and leaned back. When he looked down again, Rose was looking back up at him with smoldering, yellow eyes and sucking him down with the kind of skill that only comes from daily practice. He panted softly and gripped the sheets of his bed a little tighter. Rose’s teeth may have been dagger-like and hard, but her lips and tongue were as soft as velvet. Saliva and precum coated his shaft in a nice, slick layer of liquid, making sloppy noises every time she glukked on his dick. Finally, Leif tapped his sister on the shoulder and gestured for her to climb up in bed with him.


        “I need something to do, too. Come sit your ass on my face, I’ll get you lubed up.” He beckoned her with his hands and wiggled his tongue playfully at her. Rose smirked as she slid him back out of her mouth, drool hanging off her chin. She wiped her face and pushed Leif onto his back, then crawled over him and turned around to present him with her tight butt. Lifting her tail, she reached back and spread her cheeks wide, revealing a well-used asshole. The twins were well aware of the dangers of inbreeding, so they had made it a point since a young age to explore the hidden pleasures of anal. Leif usually topped, but he was no stranger to receiving when Rose was feeling in the mood for a good pegging. Now he was staring up at a lovely pink tailhole. She smelled like sweat and sex, and Leif was hungry for it. He leaned in quickly and took a big, sloppy lick over her ass. The two dinos moaned together, and Rose settled lower on her kneeling legs, smothering Leif with her ass. Her brother didn’t mind one bit, though, and ate deep. His tongue slipped over and around her hole, probing it gently with the pointed tip. Rose started to squirm a little and reached down to rub her clit, dipping her fingers briefly into her pussy to get her fingers slick. She started to rub small circles around her pleasure buzzer and bit her lip. 


        “Fuck, Leif, your tongue always helps me relax.” She only got a muffled “mhmm” from her brother, but she wouldn’t have sat up to let him talk now anyways. She leaned forward a little so she could reach his cock too, stroking, squeezing, and milking it to reward him for his work underneath her. His hips started to buck a little, thrusting into her tight, slippery grip. As precum started to run down over her knuckles, Rose pumped her hand faster and leaned down to lick at the tip, tasting her brother’s savory-salty flavor. “You better not fucking cum yet. I need this cock in me, so if you blow now, I’m not fucking you for a week.”  Leif merely groaned and writhed harder underneath her. His tongue pushed its way into her ass, and Rose gasped as she felt it slip around the first bend of her guts. Her pussy was drooling all over her brother’s chin, leaving his face a slimy mess. Her eyes started to roll back and her chest rose and fell with her heavy breathing. Leif felt the squeeze of her asshole around his tongue as Rose neared her first orgasm. He slurped and tongued at her hole until his jaw was sore, but he didn’t let up. Rose rubbed faster around her clit and tugged at the stud piercings in her nipples. Her cheeks were flushed and her tail was flicking erratically back and forth, knocking a lamp from its spot on Leif’s nightstand. Leif lifted his hand and slapped her ass hard enough to leave a print. Rose cried out in pleasure and spread herself even wider for him. She started grinding on his muzzle, using him like a toy. It didn’t take much more than that for her, and before long, she felt the rush of ecstasy overwhelm her in a climax. Her asshole gripped and milked Leif’s tongue, and she roared at the ceiling. Her cunt sprayed all over her brother’s chest and her thighs coating them both in her scent. After she recovered, she grinned and wiggled her ass on Leif’s face one last time and hopped off. “Whew! Shit, pervert, you love eating ass, don’tcha?” Leif wiped his muzzle and sat up, huffing as he caught his breath.


        “When it’s yours, I can’t get enough.” He shoved her down onto her back and clambered on top of her. “Can I fuck your pussy just to get lubed up?” Rose rolled her eyes and gave him a stern look. 


        “Alright, but if you cum in me, I’m gonna kick your ass.” She reached down and spread her pussy lips, showing off her pink, wet hole. Leif lined his cockhead up with it and started to rub it up and down her slit, smearing his precum all over her. She bit her lip and took a deep breath through her nose. “Don’t tease me, I’ve had enough of a hard day.” Leif chuckled and nodded.


        “Yeah, I suppose you have.” Without any further waiting, he pushed the first few inches of his cock into his sister’s waiting cunt. The twins moaned in unison as their bodies slid together, fitting with one another like they were matching pieces of a puzzle. There was little resistance thanks to Rose’s earlier climax, so Leif slid in without much effort. “God damn, I never get tired of your pussy.” 


        “Shut up and fuck me, Leif.”  Thankfully, she didn’t have to wait for very long, because he obeyed without hesitation. He drew his hips back, and then plunged his cock into her depths, shuddering as her ridges slid over his. He thrust deeper and deeper until he was balls deep in that tight dino cunt. Rose looked down as she returned her hand to her clit, rubbing it in time with her brother’s thrusts. “I hah- haven’t had anyone…nnn…in there in awhile…” Leif just grinned and fucked her faster, making wet, lewd slaps as her pussy cream splattered against both of their thighs. Just as Rose was starting to really relax and enjoy herself, Leif stopped and pulled out, breathing hard. His cock twitched in the cold air, drizzling precum like a bottle of maple syrup. Rose growled and propped herself up on her elbows. “What the fuck? Why’d you stop?”


        “I gotta put it in your ass, remember?” responded her twin. She groaned and shook her head, trying to hide her embarrassment. It felt really good when he was fucking her cunt. Maybe too good. In the haze of her lust, she had forgotten the risk of pregnancy she’d be running if Leif emptied those fat nuts inside her womb. 


Leif needed to recover, backing away from the edge of orgasm. As he caught his breath, he reached into his drawer beside the bed and pulled out a bottle of cum-lube. He lifted his sister’s legs up so her knees were against her chest, exposing her asshole to him. He popped the lid and poured a copious amount of the clear liquid over her starfish, making her shudder at the cold. He poured more on his cock and rubbed it in, then set the bottle aside. Her ass looked so enticing, covered in all sorts of liquids and just a little stretched from his tongue work. He set his tip against her hole, looked her in the eye, and pushed carefully into her ass, moaning as the heat and tight muscle enveloped his dick. Her pink ring stretched around his shaft, letting Leif see every individual ridge squeeze into her ass. It was always a little tough to fit, and Rose gripped the bedsheets and grit her teeth a little at the initial discomfort. She quickly relaxed though as the pleasure overcame the pain. 


“Oooohhh, fuck, Rose!” He twitched inside her, firing off a thick rope of pre into her ass. Rose was already wiggling her toes and letting her tongue hang out the side of her mouth.


“Fuck yeah, you love that ass, baby? Does it make you wanna nut?” She wrapped her strong legs around his hips and pulled him in deeper, making his slimy cock shove into her tailhole. She grunted as she was suddenly filled, but soon felt her tight passage adjust. Her body melted like butter, and her eyelids drooped as she felt him so deep inside her. This is what she’d been craving all day. “Fuck me full of your cum, stud.”


Leif didn’t hesitate to obey, and quickly began pumping into his sister’s ass with vigor. Her hole gripped him so tight her puckered ring pulled out a little every time he pulled his hips back. The lube helped him slide in and out with ease, and it helped her ass make moist sucking sounds as he pistoned in and out of her. He reached up and grabbed Rose’s tits, squeezing and kneading them while he fucked her hard enough to make the bed shake. Rose was starting to lose control of herself underneath him, panting and letting out short little exclamations with every thrust. She reached up and put her hands on his chest, feeling his hard scales and muscles and wanting him all the more for them. Her hands moved up to his shoulders to hang on tight, and she started to pull him in with her powerful legs, making his movements shorter, but deeper. Her moans turned to cries, and he started to rumble deep in his throat. His balls bounced off her muscular cheeks, keeping tempo with their sex as they swung underneath him. Leif felt them clench as they prepared to unload their stockpile of sperm, and he barely managed to get out a warning.


“Rose! Fuck, I’m gonna-!”


“Do it!! Oh, fuckfuckfuck, cum in me!!” She demanded and raked her claws down his back as she tried to hold on. That command was all Leif needed. He pushed as deep as he could into the hot, snug refuge of Rose’s ass and bellowed out a primal roar that was sure to piss off his neighbors. It was matched by Rose’s own outcry, the two of them shouting their pleasure to each other and the rest of the world. He came hard, his cock jumping as it fired rope after rope of hot cum into her guts. She felt the hot splash of it inside her, and her toes curled so tight her feet started to cramp. She didn’t care. She couldn’t. All thought besides how much she loved her brother’s dick had left her brain. At long last, Leif grunted and emptied the last of his load into her belly. He lay over her, breathing hard and grinning. She lay underneath him, eyes unfocused and tongue draped over her lower jaw like a red carpet. He took her mouth’s invitation and leaned down, feeding her his own tongue in a kiss that she awoke from her daze to return. They made out like this for several minutes, basking in the afterglow of their united orgasms. Leif’s cock continued to throb inside her ass, and her hole in turn clenched and relaxed around his shaft. When she finally broke the kiss, she flopped back onto the bed.


“Ahhh. Much better. Thanks, Leif.” The male allosaurus pulled slowly out of his sister’s ass and bit his lip, looking on while she tried to clench her loose hole to keep his cum from ruining the sheets. He loved leaving her with a mess she couldn’t possibly hold in.


“I’ll grab wipes and a couple towels. You need some water?” He started to get up, his legs shaking a little from the power of his climax.


“I could use some, yeah.” She pondered a moment, and then grinned wickedly. “Hey Leif, wanna earn some brownie points? Clean me up.” She wrapped her arms around her thighs and lifted her legs, showing off her cummy asshole. “Do it and I’ll let you keep my panties next time I workout.” Spinning on his heel, Leif rapidly got back in bed and bent down to slurp his load back out of his sister’s ass. His tongue worked overtime to slip inside her and scoop out the gooey goodness. He was no stranger to his own flavor, but that extra darker taste that came with it when he ate it out of a freshly fucked ass was his favorite way to eat. While he cleaned her up, Rose closed her eyes and took a deep breath, enjoying the gentle feel of her brother’s tongue below her tail. “Fuck, loser, you’re something else. Where am I gonna find a guy who eats my ass like you?”


“You’ll…mm..never…slurp..have to” he replied between licks.