Lying, cheating, what else? (Senku x reader)
Warnings: cheating with Senku, unprotected sex, begging, mdni!
Rough hands gripped your chest, pulling you flush against his back. So many calluses from such hard work, but they still felt nice when holding you like this. Skin on skin contact couldn’t be beat. You felt sweat drip down onto your shoulder, and a smirk pressing into your neck as another thrust bottomed him out inside of you.
“Can’t believe you came to my conference.” The dry laugh emitted from behind you told you that he could believe it. Other course he could. Senku knew you were addicted to the rush you got when you snuck away to see him. He liked the adrenaline it caused in him as well. That’s probably why so many people cheated on their spouses. Not that he was the cheater here.
“I couldn’t miss it, you know I just really love science.” A slap across your ass told you he didn’t believe you for a millisecond. It was fair, you didn’t really care about science. It wasn’t your interest and he knew that. Yet somehow you always found an excuse to sneak away and see him when he was gone on these weekend long trips.
“You love my dick, not the scientist attached to it.” Another slam of his hips into yours, before his strength gives out and you going from being held flush against his body, to face first in the comfy bed sheets. His hands slide down to your hips, grabbing and pulling them back against him and sending him deeper inside of you.
“Scientist attached is pretty cute too.” It was always like this, sarcasm dripping from the both of you to distract from the obvious. You had a boyfriend, and he was not the man in the bed with you. That’s why you always had to sneak around when you saw each other. The thrill of being caught was too good, too intoxicating to stop either of you. How long ago had you fallen out of love with your boyfriend again? How sooner after did you end up in Senkus bed?
Sometimes, when he was mad at you, Senku would call you a fame chaser. How else did you explain jumping from a rich playboy to a now world famous scientist? You let him think that was the reason, even if it wasn’t.
The real reason was something along the lines of genuine desire and love, but he’d never buy it. Not while you still went home to the house you shared with Ryusui.
“Better not zone out on me now.” Nails dug into your ass as he gripped you tighter, sending his length deep into you. He set a hard pace, as he always did when he spent time away at these events. He paused for a moment, shoved all the way inside of you. The tip of his length was forcibly pushed against your cervix and held there, tantalizing and tortuous. “Am I not doing enough for you sweetheart?”
“Senku, please don’t be like this.” The whine was followed by you pressing against him, taking in the way it felt to have him sitting fully inside of you. “I’m not zoning out, okay? Please—“ the begging worked, and he went back to railing you. His fingers traced over your spine, all the way down until he squeezed the plush skin under his fingers.
“I’m getting close—“ he figured he’d warn you, in case you wanted him to do something different. Instead you slammed your hips down onto his, engulfing him like you never had before. He tried to not indulge in petty fights, but he often found himself losing this one.
It didn’t seem right to finish inside another man’s partner, but with you fucking yourself onto him like this he didn’t get much of a choice. His stomach tightened up, a surge of relief and pleasure melting through his body as he pumped himself dry into you. It was a bad idea, it always was. He knew the risks, knew how it would change his life if you ended up pregnant. He knew your boyfriend would have his head. And yet…
“Senku?” Your voice drew him back to reality, the haze of his release fading. He pulled out of you and laid down, pulling you onto his chest so he could press a kiss to your forehead. “Were you zoning out?”
“That would be hypocritical if I was.” But everything he did now was hypocritical. Here he was in a hotel room, after a long day at a conference giving lectures and explaining his breakthroughs. Holding his friends girlfriend in his naked arms after fucking her. Not that he regretted any of it, but he should’ve. He was about to pulled you in close when your phone rang, stopping him in his tracks.
“Shit, it’s Ryusui.” You moved away from him and grabbed your phone off the nightstand. Hickeys and bite marks covered your shoulders and neck, clearly exposed as you stretched out to grab the phone. “Hey, what’s up?”
“Where are you, I got home and the maids said you had left early this morning.” You could both hear the aggravated tone his voice had. Recently, that’s how he always seemed with you. He never did anything about it, but you could tell he was starting to suspect you were up to something.
“I went out to this show, but it ended super late so I was going to stay the night out here.” That wasn’t exactly a lie, considering you do plan to spend the night with Senku. Though of course you left that part out.
“Fine, whatever you need. Just don’t forget about the party this weekend. There’s a lot of important people coming and I need you there.” The exasperated sigh could be heard by everyone in the room. Though Senku didn’t really care. He loved his friend sure, but clearly not even to resist stealing his girl. Senku placed a had on your thigh and began kneading it, causing you to squirm under his grasp.
“Ah, yeah. I’ll be there for that.” There went all of your focus, immediately snatched away by Senkus demanding hand. Fingers tracing patterns and equations onto your skin that made anything else impossible to think about. “I’ve got to go, it’s late.” And with that, you hung up the phone. It was barely a proper goodbye, but you didn’t care. You straddled Senku and looked down at the man who was teasing you.
“Quick call?” You shut up his mocking voice with a hard kiss.
Maybe life was out to get you. That wasn’t exactly the only explanation for why this was happening. It was just a simple networking dinner party. Ryusui was the host and you were supposed to be the charming girlfriend. It was an easy role to play, just smile and act intelligent. You’d done it tons of times before for him.
But he had never invited Senku to one of the parties. He certainly had never put Senku’s chair right beside yours, filling your senses with your lovers intoxicating scent. It didn’t make sense to you at first, why was he here? And then you heard that the business men invited were interested in branching out into scientific research projects, and Ryusui needed to look connected to that type of work.
No better way than to put your friend, the most well known scientist of the time, right at the head of the table with you.
For Senkus part, he had two reasons for being here. The first one was exactly as you thought. He was here to be a little trophy friend for Ryusui. The second part, was more personal.
His dear friend had asked him to come and keep an eye on his girlfriend, who he had begun to suspect of cheating.
The request made him start questioning his actions with you. Maybe sneaking around wasn’t the best plan anymore. He decided he wanted to stop aiding you in cheating in his friend, who clearly still loved you.
Not that he was wanting to stop seeing you himself. No, not that. He was going to ask you to break up with Ryusui and date him instead. It would’ve crushing for his friend sure, but at least they’d both get something out of it. Ryusui could move on and find someone else, and Senku could finally have you all to himself.
All he had to do was wait for an opportunity to get you alone.
“Personally I think funding more unknown research would be best for the world. There’s lots of great work that could be done, it just doesn’t have the financial backing.” Senku chimed in when needed, helping out like he had promised. The whole time he was also keeping an eye on you and watching you squirm. You were so clearly uncomfortable with sitting beside him and Ryusui at the same time. Especially since your makeup was just barely hiding the marks he left on you earlier in the week.
“You have a very capable friend here Ryusui.” Some business man laughed and clapped your boyfriend on his back while pointing at Senku. It was hell, being between the both of them. You wanted to excuse yourself and leave, but you had to wait. You couldn’t just go right at the start. So instead you sat there and smiled politely, looking cute when needed. You did this for another hour before you couldn’t take it any longer. You excused yourself in a rush, and headed off towards your bedroom upstairs. Just far enough away that you couldn’t hear the laughter and banter you were leaving behind.
“I should probably go check on her.” Ryusui had a sympathetic smile plastered on his face, but really he just wanted to find out what was wrong with you lately. It was driving him insane to deal with how cold you had become to him.
“How about I go instead, wouldn’t want to break up the party over nothing.” Senku stood and shot Ryusui a smile. Somehow it convinced the other man to calm down, and he nodded back. Then Senku was off, walking the halls and trying to remember where your room was in this expansive mansion.
He found your door finally, left slight ajar. He pushed it open and stepped inside. There you were, sitting on the bed with your hands over your face. You looked so tired just from one dinner, he almost felt bad.
“Hey babe.” His voice washed over you and visibly calmed you down, and his arms wrapping around you also helped. “You okay?”
“Just overwhelmed is all, I hate those parties.” You groaned into Senkus chest, fists balling up the fabric of his suit as you did. He just hummed in response, sympathizing but clearly with something else on his mind.
“Want me to help you relax?” That was all it took for you to cave to him, letting him stripe you off the expensive dress and watch it fall to the floor. Soon the rest of your clothes and his joined it, until you were both lying in bed kissing and feeling every part of one another. One of his hands spread open your legs, allowing him to grind his hardening length against you.
“Someone missed me.” It was stated like a fact, one you couldn’t deny as you coated his dick with your wetness. His tip teased and prodded you, the red mushroom leaking onto everything. “Bet you were thinking about me at that table.”
“You’re terrible Senku.” His tip pushed inside of you, stretching you open just like he always did. His lips pressed down on your neck, a simple comfort for the pain he was causing below. “He’s literally down stairs right now and you’re talking about getting me wet?”
“You’re letting me fuck you in the bed you share with him.” Senku let his eyes fall low, watching as you opened your legs wider for him. He slowly started to thrust in and out of you, addicted to watching you take him so well. His hands trailed over your body, taking it slow at first. He wanted to enjoy the feeling of you, not just physically. It was nice to have you all to himself, and maybe apart of him thought that fucking you in the bed you shared with your boyfriend meant he was closer to separating you both. He wanted you all to himself, plain and simple.
The noise from below grew louder, laughter drifting into your room. You watched Senku, who was too caught up in working you over his length. Your hands moved to pull him closer, his forehead pressing against yours.
“We probably don’t have long.” The sentence made his face turn a little towards disappointment. Regardless, he picked up his pace and started fucking you in earnest. Your hands met his, before soon getting pinned down to the bed as he braced himself.
“You take it so well.” His eyes fell closed as he finally hit all the way inside. Another snap of his hips repeated the motion, over and over again. “Love the way you look under me—“
“Mm, that all you like?” The teasing words were dangerous. You never said anything to Senku about a relationship between the two of you. For good reason, considering how complicated everything was. He temporarily ignored you, his fingers moving to rub circles on your clit instead. The moment he connected with you a loud mow escaped your lips, reverberating over your room.
With a grin on his lips, Senku pressed a kiss to your lips. Each thrust got harder, each movement of his fingers expertly practiced and thus perfect. You had to admit, being with someone who spent all day being so precise paid off. Everything he did was well researched and well practiced.
“Ahh— there we go.” A groan ripped from his throat as you squeezed around him. His fingers were doing their best to make you cum, and you couldn’t help that it made your walls flutter around him. He loved it all though. The houses that you slipped out, the way he could feel you sucking him in with each thrust. It was all addictive. “Gonna cum on my dick in the bed your boyfriend bought you?”
“Senku don’t-“ he cut you off by biting your neck, leaving a new and fresh mark in his wake.
“Answer me.” It was more direct, more forceful than his normal. This coming from a man who usually just relaxed back in bed while you ruined yourself on him. It was different.
“Y-yes, please can I-?” Another bite, harsher this time. And higher up, which meant the chance of it being spotted was higher too. You let out a pitiful whine, not sure what he wanted from you this time. Your hips bucked up into his, but he grabbed them and held them down. Now it was just him, using your body for his pleasure while he made you answer him accordingly.
“It’s ‘may you?’ Say it right.” The building was too much for either of you already. He was close and so were you. Yet he still wanted to make you say it. He wanted to hear you beg him, right here right now.
“Senku, m-may I cum? Please?” The words were shaken on your tongue as you tried to get them out. He didn’t say yes, just responded by pressing harder on your clit and pounding into you. A groan slipped out of his throat, followed by a dry laugh.
“Love how that sounded. Go ahead and cum, I am too.” His eyes snapped shut, focused on just chasing his and your highs. Your hands still locked together pressed harder into the bed, ruffling the sheets even worse than they were now. “Gonna fill you up— you always want that huh? Always want me to spill inside. Don’t you know— fuck, close-“
Your nails dug into the back of his hand, enough to break skin, as you came undone around him. Spasms wrecked your body, making you cry out his name over and over again as he fucked you through the feeling. Senku suddenly shot forward and kissed you, all heat and passion as he pushed inside one final time and filled you up, just like he had said he would. A few sloppy thrusts followed, making sure you were both done before he pulled away from you. Once he did, he looked you over, covered in sweat and thighs all sticky.
“Break up with him.” The words suddenly cut through the room, dousing any of the heat left over. You sat up fast, nearly knocking your foreheads together in your haste.
“What?” Was he really suggesting you leave Ryusui? He acted like he hadn’t just dropped a bomb shell on you and just put his clothes back on. He was acting like it was normal, nothing strange about it. “I— okay.”
“Really?” He had been acting bc calm, hoping you wouldn’t turn him down. But he had expected you to. Why would you choose him over his rich and handsome friend? Sure you liked fucking him on the side, but that didn’t mean you liked him.
“Yeah. After the dinner, I don’t want to cause a scene.”
After the dinner, you did just that. You broke up with your boyfriend, who wasn’t happy but had at this point suspected you of cheating. He still didn’t know who, but he swore he could see new marks on your neck that told him you had somehow met up with your lover tonight. Maybe it was one of his business friends, it had to be.
Maybe he should ask Senku if he seen anything.
