Obsession - Tamaki
Synopsis: (MxF) Tamaki is y/n's stepbrother, ever since she came into his life all those years ago he's wanted no one but her. He's tired of hearing y/n's boyfriend use her body when he knows he could do it so much better. He knows what he's about to do is wrong but he just can't seem to help himself.
Warnings: Language, DUBCON, adultery, slight domming, STEPCEST, slight tentacles, toy use, pervy Tamaki, panty sniffing, mentions of alcohol, spit, facial, oral, creampie, bruising
(3rd POV)
The dictionary definition of obsession is: an idea or thought that continually preoccupies or intrudes on a person's mind. That's exactly what was constantly stuck in Tamaki's mind every second of the day. The thought of her bent over her bed with the sheets in her mouth and tears cascading down her face while Tamaki was behind her giving her the orgasm of her life was constantly occurring in the man's head.
In their first year, she and him met when their parents introduced them to each other and announced the marriage. Ever since they had their first handshake and Tamaki felt her soft skin he was instantly drawn to her, captivated like an artist to their most finest painting. Since their first hug when he felt her plush tits brush against his chest and his cheeks turned the rosiest of red and he touched himself to sleep that night, to the first time they kissed after a heavily drunken evening when their parents skipped down and they agreed not to mention it again but Tamaki never forgot about that day. He always remembers the way her tongue slid across his and the very quietest of moans that left her mouth when he somehow gathered a handful of courage to bite her lip and pull her hair. Tamaki remembers it all, he knows it's wrong to think of his younger sister that way, but he knew it wasn't as bad as it could be since they weren't actually related, it would be okay, they'd be okay. Least, that's what he kept telling himself every night when he would steal a spare pair of panties to keep as his own just to have that smell of her next to him.
Those thoughts were running especially rampant with Tamaki hearing her pathetic excuse of a boyfriend using her as his own sex toy when she deserves to be treated better. He was locked in his room, hip-thrusting into his pillow with an ear to the wall listening to her barely moan from the "performance" the two of them were putting on.
This wasn't as loud as she could go and Tamaki knew it. He heard those lonely nights when she'd pull out her vibrator and how loud she'd get even though her face was buried into the pillow trying to keep quiet. Tamaki knows how much of a freak she is after he went into her room when she passed out and saw her lying naked with her pretty and pierced nipples laying up and open for him just asking to be sucked, it took everything in Tamaki not to have his way with her then and there.
This time was it, Tamaki had enough with fucking his pillow and whining at how pathetic it was when he could be getting the real thing if he just waited and played his cards right. So he stopped after cumming in his boxers and wiping himself clean and changing boxers, he waited until her spiky blond dog of a boyfriend left without even a goodbye to either of them, he waited until she took a shower to clean herself and get back to her room, he waited up until he heard the low buzzing of her vibrator starting up. He'd make his move now, he knows she needs him, and he's more than happy to help her.
Tamaki's heart lept out of his chest when he finally walked to her door and rested his forehead on it breathing in and out trying to calm himself. His eyes were shut into slits and his hands were shaking, he was right about to turn away until he heard it-
"Ah, fuck."
Her moan sent shivers straight to his cock. His shyness was immediately dissipated as he placed his now relaxed hand on the doorknob and turned it, practically throwing the door open in the process.
When the door hit the side of the wall the girl immediately dropped the toy and covered her bare self with her comforter. The toy rolled off the bed and onto the floor and the faint buzz in the background only drove Tamaki further to her.
"Tama, what? You okay?" She asked with a confused face.
"Lay down." He commanded, totally unlike him she thought.
"Huh? No Tamaki please leave I'm indecent right now."
"You heard what I said, lay down and open the covers." He strode farther into the room and when he got next to the bed she hugged her covers tighter to her chest.
"No-" Before she could protest, Tamaki used one of his tentacles to pull away the covers from her and her bare body was presented to him.
He kissed her with such ferocity and intimacy with one hand behind her head and onto her neck that she couldn't help but moan into his mouth. She knew it was wrong, she had a boyfriend, has, she has a boyfriend, she thought to herself. When Tamaki bit her tongue she moaned once more before pulling herself away and shaking her head.
"Tamaki I can't, what about Bakugo can't do that to him." She whispers to him while wiping her bottom lip with her thumb, not actively trying to cover herself up anymore.
"Y/n, I-I need this and I know you do too. He c-can't make you cum like I can." His normal anxious stutter comes back but his facade of dominance and confidence is still being presented behind it.
She brushes her hair to the back of her head and rubs her palms in her face and is about to protest again before a yelp rips through her mouth as she's pulled downwards on her bed and her head falls into her pillows. Her thighs are propped up onto Tamaki's shoulders and he bites into her thigh which makes her squirm and thrash, not from the feeling of it but from the conflicting emotions coursing through her.
"Tamaki n- ooohhh fuck." Her protest was cut short at the sudden long lick up her lips from the man under her. She goes to speak again but her words get stuck in her throat when she feels two slender fingers split her lips apart and a tongue graze over her clit. Her legs spazz from the sudden hit against her nerves and she's instantly enthralled at the dance happening against her pussy.
She bucks into his face when he enters two fingers inside of her, scissoring and pumping out of her to get her stretched for him. Tamaki's other hand rests on the hook of her pelvic bone and rubs circles in that area trying to comfort her and feel all of her while she takes one hand to tangle between his locks and push him farther into her pussy and she uses her other hand to twist her nipple in between her fingers.
"Holy shit Tama, yes, yes right there please." She breathes out as the man hits a particularly good spot inside of her while curling his fingers and he can already feel how close she is. He smiles into her pussy at his obsession and daydream finally coming true.
"Sssh y/n, you don't want to wake up mom and dad do you?" His words muffled from the muff in his mouth and the girl just rolls her eyes back behind her head and takes in the new speed of his fingers and tongue.
"Y-yes sir." She says, not thinking of it.
Tamaki freezes and a pang of something shoots to his cock, making it stand straighter and harder than before. He pulls away and she whimpers for him and tries to pull him back down but it's with no use as he uses his tentacles to snatch her wrists and move them above her head.
"Say it again." He says standing above her now.
"Sir."
Ecstacy shivers run through his body as he cracks his neck and smiles a wicked smile the girl's never seen before.
"On your stomach for me."
"Yes sir." The girl agrees purely motivated by the ache in her core.
Tamaki bends down to meet her at eye level and smiles as he leans in to kiss her. She smiles back with him and they share the sloppiest kiss they've ever had but the intention behind it is that most passionate thing they've ever tasted. They pull away with a string of saliva between them and the girl smiles up through her eyelashes at Tamaki as she licks it clean.
"Be good for me and take all of my cock alright?"
She nods her head and helps Tamaki step out of his boxers before his cock springs back against his pale stomach. She tries her best to hide the expression on her face but Tamaki notices it before smirking to himself at his pride. He is average size but he is girthier than she's ever seen, girthier than her boyfriend and vibrator are. She gulps and wipes away the shock before wetting her lips with her tongue and opens her mouth wide before Tamaki takes her head in his hand and guides her to his cock with his other.
"Aah, y/n, fuck." Tamaki whimpers out as he lets his head fall backward and his fingers knot into her hair and grip tightly while he waits for her to take him all the best she can. She gets halfway before choking and pulling away but she shuts her eyes and takes a deep breath before trying again and this time she gets him all the way in and Tamaki shakes in her mouth at feeling himself in her throat. His moans are quiet but so confident as he rocks his hips against her face with her now cupping his balls helping him get closer to cumming.
The sounds of gulping and moaning and still the slight buzz in the background is all that's heard in the room. She has picked up her pace with blowing him and he's holding onto her head for dear life before he reaches over and smacks her ass cheek as hard as he can and grips it tightly and he feels her moan slide from her mouth and vibrates his dick. He does it to the other one before standing up again and pulls her from his cock.
"You're such a good little sis for me huh?"
"Mhm, just for you sir."
They kiss each other slowly before he lays her onto her back and slides her up and adjusts himself between her legs, lining himself up with her.
"You ready for me?"
"Please do it, I want to cum on your cock Tama."
He moans a deep growl before he slides himself forcefully into her dripping cunt and begins his attack against her pussy. The bedframe knocks against the wall and she hurriedly reaches up and puts a pillow behind it as to not wake up their parents before her arms fall back down and grab Tamaki everywhere they can. She grips his biceps and squeezes before he hits a certain sweet spot inside of her and she lets a moan rip before Tamaki slides his palm over her mouth.
"Shut it y/n."
Her eye's shut as he thrusts harder, and their moans are quiet but forceful. Her legs wrap around his waist and her heels dig into his back as she tries to push him further in, when he does go further she feels his veins rake against her gummy walls and she feels his girth spread her wide. Her moans don't stop, so Tamaki takes the hand over her mouth, slides it down her neck, and squeezes tightly as he rams her with more force. She feels the pain in her gut and her throat but she doesn't care because of the pure pleasure she's feeling.
Her hands slide to Tamaki's back and she leaves deep scratches as he hikes her legs to her shoulders and pounds into her in the deepest spot she's felt yet. Her legs shake and her toes curl as she feels herself drawing closer. Tears are pin-pricking her eyes as the lack of oxygen and the sharp pain in her gut is getting too intense but she doesn't dare move cause she doesn't want to break from this feeling. A single tear falls and Tamaki bends down to kiss it away before releasing her throat and a deep breath is had from her but it's cut off by Tamaki's lips.
Their lips move in tandem with one another and it's as if Tamaki is giving his breath to her but she practically inhales him as she moans into his mouth. Tamaki now takes his free hand and moves it to her clit and rubs and she's seeing white. Her eyes roll to the back of her head, her legs spazz uncontrollably, her chest heaves and her breath hitches as she orgasms and tries her absolute hardest to not scream out the pleasure she just felt.
It's only a handful of more pumps before Tamaki unloads himself inside of her and his thrusts grow sloppy after he cums. They both stop and take deep pants and wipe the sweat from each other before Tamaki slowly pulls out of her and they both whine at the loss and the cum drips from her pussy.
"Fuck that's hot."
"Mhmm, towel and water please." She says with the shakiest smile and voice she's ever spoken with.
Tamaki nods and goes to the bathroom and grabs a towel and wets it and cleans her up before kissing her pussy once more as well as her lips and he quickly yet quietly runs into the kitchen to grab a bottle of water and he brings it back and helps her bring it to her lips.
"Thanks, Tama." She says with a smile before chugging half of it and sliding under her covers after setting the bottle on her dresser.
He slides in next to her and they kiss each other slowly and passionately before pulling away.
"This isn't right Tama, we can't tell anyone about this."
"Don't worry, I w-won't. You don't know how long I've wanted you."
"I do know actually, I..I've heard you fucking your fist to me before, it was hot but so wrong so I didn't do anything about it."
Tamaki didn't know what to say so his face turned beat red and he buried himself into her pillows before she giggles.
"Too late to get shy now Tama, you just fucked your little sister."
"Y-yeah I-I know." He squeaks into her pillow, not wanting to face her from his anxiety.
"Ssshh, come on Tama, it's alright."
She says before kissing his shoulder blades and rubbing the back of his head before he turns his head to her and faces her and she kisses his cheeks and they snuggle up into each other and fall asleep.