Game of the Insane (Yandere Haikyuu!! x F!Reader Oneshots)

BETRAY (PART 2)

Guess who realized they forgot to crosspost here again? This gal XD

Requested on my Tumblr

Title: Betray (Part 2/2)

Pairings: Oikawa

WARNINGS: Yandere themes, referenced past cheating/infidelity, referenced past murder, swearing, mild stockholm syndrome, depression, swearing, delusional thought process, dad vs son everywhere, Author is scared she won't make this one shot as good as everyone is hoping she will, Oikawa's a desperate sleaze bag and it makes me laugh inside

Summary: You've been stuck with Oikawa for 15 years and he hasn't changed a bit. Your son, however, has.

betray

/verb/

be disloyal to.

Oikawa's relationship with you was nearly perfect. You'd stopped screaming and crying and struggling long ago and now had normal, albeit reluctant, conversations with him. You still weren't fond of intimacy, but Oikawa never pushed you too far, remembering all too well the past that haunted him and the mistake he made because he wasn't patient.

But, anyways, life with you was nearly perfect! Meals were always done together as a family, unless Oikawa was away at a game.

A family... Oikawa dreamily sighed aloud, twirling a strand of your hair in his fingertips idly. It was just Oikawa, you, and Shun.

But Shun was where the problem came in. The reason things were "nearly" perfect instead of perfect. A thorn in Oikawa's side that only dug deeper every time he tried to get it out, a stain that only spread farther when he scrubbed at it, an itch that only got worse the more he scratched-

Oikawa had killed for you before. Multiple times. But he would never- could never- lay a hand on Shun. Even if he wanted to hurt his son, he knew you'd break. And that's the last thing he wanted. A part of him also acknowledged the fact that Shun's very existence may be a big factor in why you didn't try to escape anymore.

Your relationship with Shun was nothing romantic- just mother and son- but Oikawa would kill for that relationship. You told Shun that you loved him without prompting or begging or bargaining or threatening. You hugged, cuddled, and kissed Shun on the cheek, and let him do the same to you without even flinching.

It made sense- Shun had never done anything wrong to you. But Oikawa could see that his son was catching on to his father's ways and copying them, and, more than anything, he could see the fear in your eyes when this fact came crawling through you like some sort of diseased animal in the night.

"I love you, mom. You're the only woman I'll ever love, cross my heart and hope to die!"

It sounds too much like what he would say to you.

"If anyone tried to take me away from you, I'd kill them for you, mom."

It sounds too much like something he would do for you.

Oikawa was fully aware of your panic when Shun became possessive and clingy, but he feigned obliviousness. Maybe if Shun became a bigger enemy to you, you'd turn to the better of two evils. Oikawa had calmed down over the years after all.

Or, at least you were under the impression he had calmed down.

Truthfully, he was always plotting and biding his time until he could take your affection away from Shun and turn it to him and him alone.

"Hey! Shun!" Oikawa caught sight of his son as he passed by the kitchen, "What are you doing back so early? Shouldn't you be at school?"

Shun made a disgusted face, "Some girl asked me out."

A figurative lightbulb popped into Oikawa's mind as he saw his opportunity. A chance to make Shun put someone else over (Y/n).

"That's so sweet!" Oikawa crooned, "What did you say?"

Shun's expression was the definition of horrified- his mouth gaped and twisted, his eyes wide as saucers, his eyebrows curvy lines. "I said no!"

"Oh, did you?" The chocolate-haired setter tilted his head to the side innocently, "Why?"

"Because I would never betray Mom!" Shun's words were filled with conviction, "I'll never put another female ahead of Mom. Or a guy. Or anyone or anything. Mom is the most important person in the universe!"

Oikawa fought back a grimace.

That's when you chose to appear, face filled with concern, having heard Shun's raised, distressed voice. Before Shun could turn the situation to his favor, Oikawa spoke up, his voice smooth despite his frustration.

"Shun met a girl and she like-likes him."

"Oh, that's wonderful!" Your smile was wavering oddly. Oikawa could see the gears working in your head. The hope that Shun would finally loosen his iron hold and the fear for whatever girl he put his eyes on. The fear that her son would turn out like he did.

"No, it's not!" Shun was adamant, but his voice was softer when he spoke to you, not harsh and biting like his tone always was to his father. "I'm only supposed to have room in my heart for one person."

Oh, how Oikawa wished he never taught Shun that way of looking at the world. Maybe it wasn't his fault- maybe it was in his son's DNA to obsess over you- but he was sure he didn't help, always making sure Shun treated you with the utmost delicacy a precious being like you deserved.

As Shun cried into your shoulder, darkness consumed Oikawa's mind, that green eyed monster called jealousy clawing deep into his heart and refusing to let go. As much as he loved his son, something had to be done about this.

It was time for Shun to move on from his unhealthy infatuation with his mother, at least a little.

"You know, I'm sure Shun would love to go to the dance with you, if you have no one to go with," Oikawa sat across from Iwaizumi's daughter, who was only a few years younger than Shun, offering up his son as a sacrifice to the oblivious girl.

"Do you really think he wouldn't mind?" The young teen's eyes shone brightly with excitement at the prospect of having a date for her school's dance, especially one that was an older boy who was undeniably handsome.

"I know he'd be honored to go with a young woman like you," Oikawa smiled, victory swelling in his heart. Iwa-chan would probably kill him later, but it'd be worth it. Iwaizumi's daughter was similar enough to you that one night with Shun off with another girl could turn into more than one night.

At least, Oikawa could dream.

Whether Shun liked it or not, you'd eat up the excuse that "Iwa-chan's daughter was dumped the day before the dance, I couldn't stand to see her so sad" You'd never let Shun leave a heartbroken girl out to dry on such an important night.

Which would mean Oikawa would finally, finally have you to himself for a night- for the first time in ages. And, with a little coaching and persuasion, Oikawa could change Shun's worldview a little. Turn his obsessive personality to some random girl (probably not Iwaizumi's daughter, he wouldn't want to endanger his best friend) instead of his mother.

In the end, it'd work out. He'd never hurt you or his son, but Oikawa wouldn't hesitate to get his hands a little dirty if it'd convince Shun that moving on would be best. And wouldn't you be happy, when Shun "brings home" a daughter-in-law for you one day? Wouldn't you be happy to have grandchildren running around?

If Oikawa could convince his son of that, even a loveless marriage would take up some of his time. Children sure would take some of Shun's attention from you.

And Oikawa would finally have you almost all to himself, just like he wanted from the very beginning. He'd make sure you took his side every time, convinced Shun that getting a girlfriend would be best for you and him.

Now, Oikawa would never, ever hurt his son.

But you didn't have to know that.