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"Dude, Genos what's your deal tonight? You've been wicked snappy, " Saitama asked as he started cleaning up the remains of the hotpot. Genos had stayed to help after everyone else left, insisting he would follow after Kuseno as quickly as possible. He paused and shot his master with a long stare.
"Master, I…" he trailed off.
Honestly, he'd had a terrible day. It seemed like nothing had gone right. He'd gotten destroyed in battle again right after getting repairs done. Trying to repair himself had proven to be a fool's errand, the minor damage too widespread to possibly fix all on his own. He'd asked King to show him his video game but couldn't wrap his head around it. Saitama was distressed over losing his wallet. Having so many people in the apartment was stressful and crowded and led to everyone else eating his master's favorite parts of the hotpot. Fubuki had shown up and tried to force everyone there into her stupid group again. Genos hated when she did that, showing up and flaunting her voluptuous body in front of his master trying to lure him into doing her dirty work. It was sickening. That she thought she was somehow above his master and that he should be the one answering to her. The thought of her trying to take his place as Saitama's disciple. The thought of her taking Saitama away from him made him want to burn down the entire city with both of them in it. Worst of all, Kuseno had thought Genos had feelings for her, or he at least thought they were friends. That had put him in a terrible mood for the rest of the night. He did not like Fubuki in the slightest. He sighed heavily.
"I don't think I can compress it into 20 words or less."
Saitama clicked his tongue, "that bad huh."
Genos ran his hand over his partially shattered face, "it's been a long day."
Saitama moved closer to him, "is there something I can do about it?"
Genos tensed slightly as Saitama's hand reached out to rest against his waist, "you shouldn't bother yourself with it, Sensei."
"Come on, don't give me that," Saitama said, nudging Genos to make him turn so they were face to face, "I know you didn't hang back here just so you can help me clean up dinner. What do you want?"
Genos looked down, no sense trying to keep things from his Sensei. Truth be told he was feeling extremely inadequate. He needed to prove to himself that he deserved to be his master's disciple. He needed to make Saitama not want to even look at anyone else, especially not Fubuki.
He swallowed dryly and asked, "Can I suck you off?"
Saitama raised his eyebrows, "Okay," he paused, looking over at the floor where King still lay unconscious from the hotpot scuffle. Saitama jerked his head towards him, "Are you sure you want to with him still here?"
Genos pointed his scanners towards King. The man was completely dead to the world. He may as well have been in a coma. Genos fixed his gaze back on Saitama, "I'll keep an eye on him just in case but I don't think he'll be waking up any time soon."
"Alright if you insist," Saitama let his hand fall away from Genos's waist. He glanced over the rest of the mess from dinner, "how do you wanna start?"
"Allow me Sensei," Genos sprung into action, running off to get the futon laid out on the floor. Saitama continued cleaning half assedly until Genos was laid on his back on the futon looking up at him expectantly.
Saitama walked over, opening his fly as he went, "You want me to sit on your face?"
"Please, Sensei."
"Alright," Saitama said as he pushed his pants and boxers off. He was kind of expecting that, Genos was in one of his moods tonight. Saitama throat fucking him usually did the trick when he was feeling jealous.
Stepping out of his discarded clothes, he moved to stand with his feet on either side of Genos's head, watching for a split second as Genos gazed up at him and licked his lips before lowering himself into a kneel. Genos's hands came up to caress the backs of his thighs as he settled into place. Saitama grabbed himself by the base of his cock and held it to Genos's lips. Genos picked his head up to meet it halfway, brushing his lips against it softly, his eyes fluttering shut from the smell and touch. Saitama's dick pulsed at the attention, starting to stiffen up from the gentle kisses Genos put there.
Genos's lips parted, letting it slip in between them into the warm cavern of his mouth. Saitama let out a soft 'ooh', rocking his hips forward to push it in the rest of the way. Genos wrapped his arms around Saitama's hips, pulling him in deeper. It was no effort to take his master completely into his mouth when he wasn't fully erect, and Genos loved feeling it stiffen and grow until it easily breached his throat. His fluid pump systems activated in his mouth, synthetic saliva pooling under his tongue and leaking from the corner of his mouth over Saitama's balls.
Genos sucked and licked at its underside like a man possessed, pushing his head up off the ground to get more of it inside him. Saitama let him, bracing one hand behind him on his lower back to straighten his spine out. He knew he'd end up hunched over eventually so he tried to keep it straight for as long as he could. His eyes crossed and shut, his jaw dropping open as he felt the head of his cock slide into the tight heat of Genos's throat. Genos's lips pursed around him as he watched Saitama's reaction from the ground. His hands slid over Saitama's smooth skin, reaching up until they grabbed onto his buttcheeks and squeezed.
Saitama laughed breathily and reached down to get a hand on the back of Genos's head. His fingers wormed their way through Genos's hair until he had a decent grip on the back of his skull. He pulled Genos's head back, then slowly forward again. After a few seconds, he started to do it faster, his cock head poking down Genos's throat and leaking pre every time he swallowed. He made heavy, breathy noises halfway between moans and sighs. Genos buzzed softly underneath him, his internal workings humming with arousal.
Saitama brought his other hand to the back of Genos's head, holding it steady as he fucked the cyborgs mouth. He stood up on his knees, getting them planted securely under him. Genos's metal skull was a familiar shape and weight in his hands and he jerked it tight against his pelvis again and again. The cyborg's fingers trembled on his ass slightly as his master took full control, pulling his head on and off his cock at his own pace.
Saitama's heavy breathing started to get more vocal the longer he spent using Genos's head like a fleshlight. He took one hand off the back of Genos's head to wipe the sweat off his forehead. Genos held his head still, face pressed tight against Saitama's pelvis, the shorter man's cock fully sheathed in his throat. The hand that remained on his head was lax, Genos holding himself in place entirely of his own volition. He swallowed, making his throat squeeze down the length of Saitama's cock.
Saitama's hand tightened on Genos's hair, holding the back of his head in place while he thrust his hips. Watching his cock disappear into Genos's mouth again and again. Drool ran down the corners of Genos's mouth and his eyes went crossed. Saitama rumbled softly at the feeling of Genos moaning around the cock in his throat. He slowed down, rolling his hips in a circular motion. Genos squirmed under him, grinding his hips against nothing.
Genos grabbed Saitama's hips, tugging at them to get Saitama to fuck his mouth harder. Saitama huffed and yanked Genos's head back, grabbing him by the bangs and pinning his head to the floor. He shifted his weight, leaning forward with one hand braced on the floor and started fucking down into Genos's throat. Genos's hands went limp on Saitama's hips for a moment, his eyes going dark from the sensation of Saitama's cock plunging so deep into his throat.
Saitama fought to hold himself back, not wanting to damage Genos any worse. He could feel Genos's face cracking more, flakes of it coming off and sticking to his sweaty skin or falling to the floor with a soft crackle. Sweat ran down his forehead and dripped to the floor he was hunched over. His breath came in ragged pants. He was getting close, he could feel his hips trembling every few seconds, his balls pulling taught and precum dribbling out in anticipation.
His legs squeezed around Genos's shoulders and his body pitched forward, dropping down to his elbow and humping Genos's mouth desperately as he came. He moaned, his breath fogging the floor. Genos dutifully swallowed each pump Saitama shot down his throat, stroking the backs of Saitama's thighs lovingly.
Saitama stayed in place for a few seconds as his breath came back. Genos obediently held his master in his mouth until long after it was done spurting and starting to soften.
"Mmh," Saitama grunted as he rolled off Genos to sit next to him on the futon. Genos blinked his eyes back open and sat up slightly.
"Thank you, master," the cyborg said breathlessly, wiping the artificial saliva off his chin.
"Mmhmm," Saitama nodded distractedly, his eyes focused on the tent in Genos's shorts, "you gonna deal with that before you head out?"
Genos wordlessly grabbed his cock through the fabric. His arousal systems had worked him into overdrive from having Saitama's cock in his mouth. He smacked his lips a few times, "I probably should."
"Here," Saitama nudged Genos's side, "switch spots with me."
Genos obeyed, crawling out of his spot and watching Saitama flop down onto it face down. His eyes instantly focused in on Saitama's bare ass, which the older man propped up slightly once he got into place. Genos's erection jumped in his shorts at the sight but he hesitated.
"Master, you haven't been properly prepared," he pointed out, awkwardly sitting on his knees behind Saitama.
"Oh come on," Saitama huffed, "just put it in, it's not like you can hurt me."
"Yes, master," Genos responded, quickly shoving off his shorts and knee-walking in between Saitama's legs. He put his hands on Saitama's ass, cupping the bottoms of each cheek and squeezing. Lubricant dribbled from the tip of his cock in anticipation as he spread them apart. It dripped down between them when he leaned forward. He reached down to smear the lube against the tight puckering hole with his thumb before grabbing his cock and lining it up.
Saitama grunted and winced when the head popped in. The discomfort faded disappointingly fast and he sighed, shuffling his legs wider and arching his back slightly. Genos held him by the hip, breathing heavily and puffing out steam. He wasn't moving, just holding the tip inside letting the lubricant dribble in. Saitama shivered a little at the feeling; the lube was heated and it felt disturbingly like getting pissed in as it streamed gently inside.
"That's good," Saitama assured him after a few seconds, "go ahead."
Genos dropped down with his chest against Saitama's back, wrapping his arms around Saitama's waist and plunging his cock in all at once. The cyborg let out a throaty groan as it was engulfed, arching his neck before burying his face between Saitama's shoulder blades. He clutched his master's body tight against his as he started thrusting his hips rapidly.
Saitama groaned, letting his head drop against his forearm as Genos's cock assaulted his prostate. The steady rapid pumping of Genos's hips was mechanical, each thrust punctuated by a short whir from the pistons in his pelvis. He was moving fast, not wanting to draw it out too long and make Dr. Kuseno wait.
He didn't want to draw it out but that didn't stop him from doing it just a little. It took him a good few minutes before he decided to ramp it up and switch his vibrator on. It made Saitama moan and clench tight around his cock. Genos felt his fingers dig into Saitama as he felt his orgasm building. He could tell Saitama was getting close too by the way his asshole fluttered around his girth and how his breathing got all ragged and loud.
But he needed to make Saitama cum first. He was desperate for it. Desperate to please him, to feel him seize up and clench tight around him. The only way he would let himself cum was when Saitama milked it out of him. Even as the vibrations in his cock grew intense enough to make his eyes water. Saitama gasped, turning his head so his cheek pressed against the floor. His whole face and head were flushed a deep pink.
“I’m gonna cum,” he moaned, his fingers twitching as they curled into fists against the floor. Genos squeezed him tight, grinding his cock deep into his master as the shorter man came, throbbing tight around him. Tight enough to make Genos whimper into the back of Saitama’s neck as his thighs gave out. It hurt. Saitama’s muscles were truly incredible. It wouldn’t be the first time Saitama came so hard he pulled Genos’s dick clean off. But Genos managed to keep it attached as he pumped a thick load of cum deep into Saitama’s ass. Each squirt accentuated by a short mechanical whir from his fluid pump systems.
Saitama sighed as Genos switched his vibrator back off, reaching back to touch the back of his head. He felt more bits of Genos’s face flake off and stick to his sweaty back as Genos sat up and slowly pulled out. The head of his cock caught slightly at his rim before it popped out followed by a thick glob of his cum.
“There, you feel better no-” Saitama’s question was cut off by a hiss as Genos leaned down to lick the cum off his asshole. He put his head down on his forearms and pushed back a little, just hard enough to get Genos’s tongue to poke into him a few times before Genos sat up fully.
“Yes, much better Sensei,” Genos said, leaving even more face crumbles stuck in between his ass cheeks.
“Alright,” Saitama said, rolling over onto his back and pulling Genos down into a quick hug and kiss, “you better head back to the lab before your face falls off the rest of the way.”
“Yes, Sensei,” he responded, kissing Saitama on his forehead, then the top of his head, “I love you.”
“Love you too,” Saitama answered groggily. He flopped back down and watched Genos pull his shorts back on and pack up to leave.
He craned his neck to look at where King was still lying unconscious on the floor. He hadn’t moved that whole time. Saitama considered going over there and checking on him but he just nutted twice in the span of like 15 minutes and barely had enough energy to go to the bathroom to shit the rest of Genos’s cum out before throwing on some pajamas and immediately going to sleep.