WARNINGS: Graphic depiction of autistic meltdown, self injurious behavior
It was the last set of Kozume Kenma's first high school volleyball game, and he wasn't doing to well. He played in middle school, of course, but that was a lot different than being the setter, the "brain," of a powerhouse school such as Nekoma. The crowds were bigger, he was depended on more, and the games were more serious. He could see the nervous looks from his boyfriend, Kuroo, but he kept shaking his head. He needed to finish this game, needed to help his teammates through, needed to win. Besides, being pulled out wouldn't stop him from getting overloaded, it's too late for that now anyways. All that would happen is that his inevitable meltdown would come faster, and he'd rather not have it in front of this huge crowd.
With shaking hands, he put up a set to be spiked. The ball went through the blockers, and hit the ground, scoring the winning point for Nekoma High. Immediately, screams came from the crowds, making him instinctively clutch his hands over his ears and screw his eyes shut.
The next 20 minutes were a blur. He was vaguely aware of being lightly pushed by someone (Kuro, that smell was Kuro, Kuro was safe) into a line to thank the other team, vaguely aware of Kuro nudging his arm when he had to bow, vaguely aware of being lead away. He could hear the team asking where they were going (including insinuating that they were getting... intimate in celebration of their win, which earned Yamamoto a slap from Yaku), but coach told them all to change and go home, giving Kuro a nod and slipping him the key to his office.
Kenma barely held out until they got there, and as soon as his boyfriend turned to lock the door behind them, he practically jumped across the room (to avoid hurting Kuroo accidentally), sat against the wall, and lost it.
He'd already been hyperventilating, and in the hall tears began to fall, but once he relinquished control he started stimming erratically. He rocked back and forth hard enough that his back slammed against the wall (as would his head if he wasn't leaning forward so far), throwing off his shoes and socks, and lashed his arms out, hitting walls, the desk, and himself. He also stimmed vocally, giving small, throaty yells.
Kuroo had seen enough of these to know not to step in, not yet anyways, so he sat against the opposite wall (after dodging the shoes). Coach didn't have anything valuable in his office, so he didn't have to worry about Kenma breaking anything, but he had to watch his boyfriend close.
Usually when this happened, Kenma had a period of erratic stimming before the true SIB started, and this was no different. If you touched him right away, it'd get worse, but since he wasn't at too big of a risk to himself it was fine. Once he really was in danger of hurting himself, then he was free to try to touch by his parents or Kuroo (with warning of course), so that's why an eye had to be kept on him.
After 5 minutes of rocking, flailing, and yelling, Kenma dropped his arms, wrapping one around his torso to dig his nails into his side, and biting the wrist of the other. That was Kuroo's cue, so he walked up to him, crouching so the panicked boy didn't feel trapped, and slowly reached his arm out to take the hand on his side. When Kenma didn't flinch away, and instead leaned closer, Kuroo took the hand and held it, moving the younger between his legs and crossing them over for DPT, and began rocking with him (slower and gentler, but in a wide motion to stay calming). He pulled a chewie (Kenma's favorite, a mushroom shape that was also the perfect shape to suck on when he didn't feel like chewing) from his pocket and gave it to him, pulling his other arm from his mouth gently. Kenma put the chewie in his mouth, but sucked on it and began whining, scratching his wrist, lightly but scratching all the same.
Kuroo took it in stride, having seen this happen even when Kenma wasn't in a meltdown. He wasn't looking for something to chew on, as much as he was looking for pressure on his wrists. The taller boy adjusted himself so he wasn't leaning onto his arm, and took hold of Kenma's wrists, firmly but not enough to hurt. The younger immediately slumped into his boyfriend, still crying and breath still uneven, but much more at ease and humming lowly.
