HAIKYUU HEADCANONS!!

Reacting to you slapping their ass

(THIS ONE IS WEIRD IK. It sounds really weird but it's been living in my head rent free. Like you know if you have a friend [especially a boy] and they're caked up for no reason so you just give it a smack? [if yall are THAT comfortable with each other] Those are so funny to me so I'm doing these)

-Rintarou Suna

You were walking behind your boyfriend for once, since he's usually the one who drags behind or by your side so you got a whole new view of him. "Damn, his posture is THAT bad?" was your immediate thought but there's other things you noticed. Despite his height, your eyes trailed down to his rear. "Gah dayum, he got more cake than me." He was too distracted by his phone while he was walking to even hear your surprised noises so you took this as an opportunity.
"bro..." You immediately run away laughing as Suna turns around to look at you with a confused expression. You're too busy laughing at his reaction to think about how this man is already plotting your embarrassing fate. He holds this plan for a while, waiting til you walk ahead of him and you guys get to your destination. It's not until you find the twins to greet them that Suna comes up behind you, a loud smack heard from below as you gasp, almost crying out at the pain. "RIN-" "Hey guys." He ignores the expression of Osamu and Atsumu as he greets them, also ignoring the way you're rubbing at your ass from the impact.

-Hajime Iwaizumi

You're at the supermarket, grocery shopping with your precious Hajime. He's pushing the cart, looking down at the notes app he has open on his phone to see what you guys need. You're just admiring everything about him. His back muscles, his grip on the handle of the shopping cart and- wow. That ass, damn Iwa. You're gambling between life and death by doing this but the amount of times Iwa has managed to get you to squeal in public by squeezing or slapping at your ass is countless so this one time shouldn't hurt. You do this quickly, a light smack on his rear as you prepare yourself to run but Iwa already has your wrist in his hand, fire in his eyes as he looks at you. "H-Haji, let's be rational.. You know I love you-" You barely get to finish your sentence as Iwa turns you around in one swift motion, his hand placing a HARD smack on your ass. He glares at you for a second before continuing to push the cart, ignoring your whines and limping behind him.

-Tetsurou Kuroo

He's so confused. Kuroo was just trying to go shopping with you, picking out shoes you've been wanting and clothes you've been looking at online. So what did he do to deserve a humiliating smack to his behind? He tenses up with a shoe box in his hands, his cheeks flushing with pink as he excuses the people around him. He slowly turns around, his smirk different than usual. It looks mischievous, evil even. You're already speed walking into the changing rooms, saying quick 'excuse me's at anybody you pass by until you make it in. As you go to close the door, Kuroo's shoe stops the door from closing. "Tetsu..." "Don't Tetsu me. You knew this was coming." He steps in, closing the door behind him. All you could do was swallow the lump in your throat, looking up at him as he gives you that mischievous smirk from before. (I'll let the imagination run wild with this one)

-Wakatoshi Ushijima

He don't know what's going on. First he was asking you what flavor ice cream you wanted and now he's frozen (no pun intended) in shock and confusion. Ushi turns around and asks you, "Why would you do that?" like genuinely, no sarcasm, no anger or embarrassment. He just wants to know why you smacked his ass for no reason. All you could do is giggle and wrap your arms around him bc he's adorable, "for no reason." You also used this as an opportunity to smack it again and you can feel him tense up this time, looking up to see him clear his throat, trying to ignore how his cheeks burn up.

-Tooru Oikawa

"Damn.. my boyfriend so fucking flat." Is all you can think as you walk behind him. Of course you were gonna smack it anyways and taunt him for having nothing there. So your hand "somehow" just made it's way to his ass- or at least where his ass should be and you look up at his flustered expression. "Seriously, Tooru, you've gotta start doing squats." Oikawa looks at you as you continue walking in the most offended face possible. "Tch, maybe you should join me." He manages to say after snapping out of his shocked state. All you could do is scoff back. "Fucking liar. I'll get you some yoga classes though cuz wow.. you flat as fuck." His mouth drops in shock as you continue mumbling under your breath about how you cuffed a mf pancake.