Weird concept, but I love this trope so much I can't stand it. Oikawa reverts back to seven years old, and Iwaizumi has to deal with it.

"Mmgh- -Iwa- -aagh- -chan."

His friend's breath was in his ear, hot and heavy, accompanied by the soft press of lips. Large hands were on his hips, and the owner of which was using his grip to pull himself out, leaving a small mess that trickled out between Iwaizumi's cheeks. The tanned teen worked on catching his breath, his teeth still numb from gritting them as hard as he did when he came. Now he was slackjawed and barely keeping himself upright on his knees, with Oikawa spreading his cheeks and squishing them together. "I came a lot. I should've pulled out before, huh?"

No, I don't really mind it. It feels good. Iwaizumi felt too embarrassed to say, so he instead swatted Oikawa's hands away and slowly laid himself down on the bed. "Whatever," he felt too breathless, and he was sure his face was as red hot as it felt. Oikawa always understood what he really felt, no matter what he said.

"Whatever? Didn't it feel good at all?" Oikawa asked, getting right to the point as usual. Iwaizumi wasn't even used to the mind blowing sex yet- - and he definitely wasn't used to talking about this kind of thing. He turned his face away, grumbling into the pillow. "It's fine. You do whatever you want, anyway." No, that wasn't what he meant at all. Why couldn't he just drop the pride and admit it? Iwaizumi turned his back completely, slipping off the bed to clean up.

"... Ugh." Oikawa plopped down on the bed without another word, stewing in his bad mood. He wasn't leaving though, and that was some relief to Iwaizumi, who still wasn't sure how to handle himself. He thought this would all get better with time, but his feelings never grew less intense. He always wanted Oikawa, and he knew Oikawa wanted him. It was a little... scary.

When he came back, Oikawa was already in his shirt and boxers again, curled up on the far side of the bed. Iwaizumi carefully picked up his side of the blanket and wiggled underneath, blinking back tears of frustration, before the soothing sound of Oikawa's breathing lulled him to sleep.

Iwaizumi couldn't remember his dream, but he felt like it was on the forefront of his mind. He was aware that it existed, but he couldn't remember what it was.

Little pats felt over his face until it was numb, and Iwaizumi guessed that Oikawa's fluffy cat had climbed over his face, as it was prone to do. He reached for its arms, even in his sleep his grasp was gentle, slowly prying the little hands off his face.

"Ah! Iwa-chan's awake!"

"Well yeah, you'd be too if you had..." Iwaizumi's eyes snapped open as his thumbs grazed over soft, thin wrists. Those were Oikawa's eyes, brimming and dark, but Oikawa's face was definitely rounder, and smaller. Iwaizumi's eyes flickered down as the smaller body hovered over his, seeing Oikawa's shoulder exposed in the shirt he practically drowned in.

Oikawa sat up straight on Iwaizumi's chest, his wrists wiggling out of Iwaizumi's weak grasp. "You're really Iwa-chan!" His voice was higher, and softer, and everything about him glowed brilliantly. Iwaizumi was still speechless by the time Oikawa leaned over him once more, those little hands buried in his black hair, his face hovering inches above Iwaizumi's own. "You're all... grown up, though."

Iwaizumi had always been weak to Oikawa when they were little, but this time he was too shocked to fall for Oikawa's charms. Even if Oikawa was currently seven years old.

Without a second thought Iwaizumi was gathering the child in his arms, the brunette giggling as he was ushered downstairs in Iwaizumi's arms, his little head bouncing with each bound toward the sounds in the kitchen.

"Mom! Dad! Something's happened to Oikawa!" He wailed, swinging into the kitchen little but his boxers and a shirt. And one sock. Oikawa was wiggling in Iwaizumi's arms with a laugh, his eyes shining in Iwa's mother's direction. "Hi, Auntie!"

The older woman stared in silence for one second, then two as she stood in her apron, and Iwaizumi's father disinterestedly kept his eyes on his paper.

"You're right! Something did happen!" She came closer, her arms stretched out and her pretty grin wide. "Oikawa became cute and little again!" Oikawa eagerly climbed into her arms and she showered him with affection, the weirdness of this entire situation lost on her. Iwaizumi watched the two, dumbfounded, his arms limp by his sides.

"How old are you, Tooru-chan?"

"Seven and a half!" The boy proclaimed proudly, even counting his age on his fingers for the older woman, who cooed in delight. "Of course you are!" She poked his chest, earning another adorable giggle out of him. Iwaizumi found his heart swelling, even amidst the chaos.

"Aaand who's your favorite person in the whole, wide world?" She asked, earning Iwaizumi an immediate glance from Oikawa. Then his gaze turned shy, and he was lowering his expression, which quickly filled with color. "Iwa-chan~" he spoke softly, and something like the dull clang of a bell sounded from within Iwaizumi.

"So he's still in his Iwa-chan phase. Well, I guess he never got out of that phase." Iwaizumi's mother spoke, gingerly lowering Oikawa to the ground. "Well, it seems like we'll just have to watch him until his parents return. Their flight's probably landed in Hawaii, by now."

Iwaizumi hadn't thought of that. He looked down, worriedly at Oikawa, who was pulling at the hem of his shirt. "Where's little Iwa-chan?"

The taller of the two sighed exasperatedly, still yet to feel reality sink in. "There is no little Iwa-cha- -me. It's just me."

"Oh," Oikawa replied a little sadly, shuffling his feet. "Did he get lost?" It seemed as if Oikawa had as much of an understanding of this situation as Iwaizumi did. His expression softened.

"... No. He'll be okay. He's your Iwa-chan- -he's probably on his way right now." Iwaizumi squatted on his heels to be a little lower than Oikawa's now limited eye level. He could feel the warmth staining Oikawa's cheeks now, the boy nodding his head with more cheer. "Yeah! You're right. I'll wait for him with you, then."

"You've got school though, right 'jime?" Iwaizumi's father spoke, his deep voice instilling fear in Oikawa, who he'd never learned to change his voice for. Oikawa immediately cowered behind Iwaizumi's leg, trembling a bit. God this brought on a deeply rooted nostalgia Iwaizumi couldn't place.

"I-I'll go to school with you." Oikawa peeked warily from Iwaizumi's leg at the scary sounding, large man, before hiding again with a shiver.

Iwaizumi rolled his eyes. "I can't take you to school." Then he made the mistake of looking down.

Oikawa's eyes looked bigger somehow, and now they were watery. It was a face he'd always been weak too, but with a pained heart he was still going to deny Oikawa this boon.

After about twenty minutes of bawling, sounding for all the world like a poor, innocent child being abused, Iwaizumi's parents convinced him to let Oikawa accompany him at least to volleyball practice. So Iwaizumi had no choice.

"Woah. It really is Shitty-kawa." Hanamaki poked the little one's nose before practice started, earning a quizzical arch of a thin, small eyebrow. "Shitty!" Oikawa chirped, and Iwaizumi smacked Hanamaki.

"So he just woke up like that? What were you doing the night before?" Matsukawa's eyes were lidded, as usual, and Oikawa was studying the lines of a volleyball they'd given him. Iwaizumi looked down into his lap, where Oikawa sat. "Well..." Iwaizumi sighed, stewing it over. Matsukawa and Hanamaki shared a look.

"Disgusting."

"I knew they've been going at it like animals."

"Oi, we weren't- -" Iwaizumi attempted to defend himself, before his honesty betrayed him and he was sulking, shrugging his shoulders. His friends had never really judged them before for their previously outed relationship. And he felt too troubled and exasperated to argue. He gave up, deciding not to give it much attention. "We fought after, though."

"About what?"

Iwaizumi shrugged his shoulders again, looking down at the top of Oikawa's hair whorl. "Something stupid... but maybe... I don't know... it triggered this. And he's angry at me." Oikawa tossed the ball up a little ways before catching it, before his eyes gleefully shined up in Iwaizumi's direction.

"Maybe he'll never turn back. And it's all my fault."

"Ah, Iwa-chan!" Oikawa scrambled up on Iwaizumi's lap, little hands on the others shoulders. "Don't cry!"

"I'm not crying- -" He did look miserable, but no, he wasn't tearing up.

"Ooh!" Oikawa seethed in childish anger, turning his angered expression toward the other two. "If you guys make Iwa-chan cry, 'm gonna beat you up!"

The two shared another look, then feigned remorse, immediately bowing their heads to Oikawa. "We're oh-so sorry, Your Eminence."

"Heh! Yeah." Oikawa's hands fell to his his, before his expression withered and he was looking up at Iwaizumi. "What's emme- -... eminesesense?"

"It's a good thing," he dryly remarked, earning a satisfied huff out of Oikawa, who pointed accusingly in their direction. "Good. I'll spare your lives! But. You have to give me and Iwa-chan all your money."

"What?" Iwaizumi leaned down to capture Oikawa's attention, frowning even as those little arms naturally looped about his neck. "We're not taking their money."

"But I wanna buy Iwa-chan some milk bread."

"I'll buy you some, calm down."

The exchange was hilarious to the two other teens, who'd since raised their heads and grinned at each other, before the whistle blew and practice commenced. Their coach was a little frustrated by the fact that they were missing their main setter, and with one look at Oikawa as he was then had him silent about the matter. So Oikawa promised Iwaizumi he'd be good, sitting on the sidelines, and watching his best friend's powerful form.

"You were so cool!" Oikawa's shrill voice was incredibly happy, swinging on Iwaizumi's arm as they walked home. The darker teen scoffed a little, but couldn't help how happy this conversation was making him. "It wasn't that big of a deal."

"It is! You were like- -SLAM!" He let go of Iwaizumi's arm to momentarily swing his in the air, a laugh following as he caught up to his best friend and held onto his hand. Iwaizumi gently squeezed his fingers around it.

"You're much cooler, grown up."

Oikawa heard the statement, but moreso how Iwaizumi said it. He sounded sad again. Oikawa looked down at his feet as he walked, quiet in thought. "I'm really cool? Even cooler than Iwa-chan?"

"Yeah," Iwaizumi replied, biting the inside of his cheek. What Oikawa wouldn't give to hear this. "I'm just... grumpy. And stupid." Iwaizumi voiced his thoughts aloud, more to himself than to the young one. "'m never honest about what I'm... really feeling. And now I screwed up, big time, 'cause Oikawa probably hates me." Now he did feel like crying. Too bad he didn't feel like breaking down in front of a seven year old. But he was close.

"Hey! Hey~" Oikawa tugged on his arm, and Iwaizumi stopped in his tracks, eying the shadow of his lover. Oikawa was still trying to pull him down, so Iwaizumi complied in the middle of the sidewalk, letting Oikawa him in close for a hug.

"I don't hate you." It was simple, and the voice was soft and high. But it was Oikawa.

"I know. I just..." Iwaizumi's voice quivered, and he wrapped his arms about the smaller form of his lover. "I want you back."

How could a seven year old understand this? He was placing too much weight on these small shoulders, another reason for Iwaizumi to despise himself.

Oikawa's petite hands patted Iwaizumi's broad back, trying to comfort him. "I know you want big me back. It's okay. I want little Iwa-chan back too." The pain in his voice was enough to get Iwaizumi's heart breaking all over again. "I think aliens switched us up. That's gotta be it."

"Aliens, huh?" Iwaizumi let out another sigh, but this one was shorter and more resolute. He pulled back, flashing Oikawa a small smile. Oikawa looked taken aback, then pleasantly surprised. "Thanks, Oikawa. I feel much better."

Oikawa's mouth opened, but nothing came out. His face flushed horribly red, and his hands were fisting his own shirt. "Your smile's really- -really nice."

Ooookay. Iwaizumi's lips quirked up further into a grin, and he started to stand. "Alright, bud. Let's go home."

"Ah, milk bread first!" Oikawa hopped, taking Iwaizumi's hand again.

"Yeah."

They returned home, and Oikawa was made to finish his snack before they entered the home, less Iwaizumi's mother get mad at them for eating sweets before dinner. The two were inseperable, especially when Iwaizumi's father came home and when it was time for a bath, Oikawa insisted on joining him.

"Do girls like me?" Oikawa asked as he sat in the tub, already scrubbed and rinsed, every bit as girl crazy as he was when he was older. Iwaizumi smiled at that. He knew he was giving Oikawa a big head, but there was no point in shaming or humbling the little dude, not when he smiled so brightly. "They like you a lot." Iwaizumi rinsed out his own hair, hanging up the shower head before joining Oikawa in the large tub.

Oikawa fiddled scooted to the side, his hands on his knees as they folded up to make room for the other. "Does Iwa-chan like me a lot?"

Iwaizumi felt guilty, and not just because Oikawa's big round eyes were boring into his soul. Why was it so easy to tell Oikawa all these things now? Why couldn't he be as honest before?

"I like you so much. More than anyone." Iwaizumi took pleasure in the way Oikawa's face lit up. Iwaizumi tried to relate it to the way a seven year old thought. "I like you more than... catching beetles."

Oikawa's eyes widened. "That's a lot!" He splashed in the water and wiggled on over, taking a seat in Iwaizumi's lap. "I like Iwa-chan too... though sometimes, you're a little mean."

"I know." Iwaizumi's fingers slowly swept through dark, damp tresses of Oikawa's hair. He looked off in the distance as Oikawa fiddled with his lap. It'd been a long time since he'd had a bath with Oikawa. Or at least, a chaste one.

"Look! I can make it stand!"

Iwaizumi yet again made the mistake of looking down, seeing exactly what Oikawa had been fiddling with. "Erkk- -" Iwaizumi choked, quickly averting his eyes and feeling the awkwardness roll in, in waves. Thankfully in the next moment, Oikawa was distracted with something else, the little weirdo making sound effects with the few bath toys they'd jimmied out of storage, and Iwaizumi was grateful they did. He let out a sigh of relief and decided to voice one of the bath toys, playing an alien villain, who for some reason had to be ugly, so Oikawa could play the hero, who for some reason had to be incredibly handsome and good with the ladies.

Oikawa was exhausted by the time they left the bath, insomuch that Iwaizumi ended up carrying him back to his room. He dried him off and dressed him, smiling to himself when Oikawa lifelessly lifted his arms to help the pajama shirt on. Once the two were dried and clothed, they were getting underneath the covers. The bed felt so much bigger, without Oikawa as big as he usually was.

The little brunette yawned, nuzzling his face against Iwaizumi's chest. "I hope the aliens bring Iwa-chan back."

Iwaizumi thought about it. He wanted Oikawa back too. He wanted to tell him how sorry he was, and how much he loved him.

"Night, Oikawa. I... love you."

"Mhm!" Oikawa complied with a smile in his voice, his little lips kissing the bare skin of Iwaizumi's neck. "Me too."

It felt like something had lifted off Iwaizumi's shoulders, then.

The spell was broken.

Spell, alien technology, some weird weird act of a higher power. Whatever it was, it'd gone the next day.

Oikawa, as grown as he'd been the day before, was sleeping beside Iwaizumi.

He woke first this time and his heart leapt up to his throat. His eyes snapped open and his arms were reaching out for Oikawa and hoarding him all in, violently squeezing his love into him.

"Ghh- -Iwa-cha- -an!" Oikawa woke, alarmed, his hands finding some place on Iwaizumi's back to pat quickly, before he was trying to pry Iwaizumi off. So the overly eager teen readjusted his hands to hold him more gently, never lessening his grip.

"You're back." Iwaizumi's voice broke, and Oikawa's body went still. His voice dropped, no longer panicked. "Where did I go?" His hands ran over Iwaizumi's back, who melted at the touch. "Bad dream? ... 'm here though now, Iwa-chan."

"I was..." Lonely. Scared. Before, Iwaizumi had been too embarrassed to say how he felt. Now, it was like he couldn't say enough and there was nothing that could describe the way he felt.

Oikawa hushed him, pulling away slowly to look Iwaizumi in the eyes. Mischief glinted in his eyes, but his expression was calm, uncharacteristically thoughtful. "You'll get used to being in my arms. Won't come easy or quick, but you'll get used to it." Iwaizumi's hands that clutched Oikawa were slowly loosening their hold. "And when you do, you won't be as embarrassed. You'll stop dreaming those dreams. Because I'll keep you warm and safe." It was everything and more Iwaizumi needed to hear. Oikawa would be there for him. He understood why coming to terms with his feelings wasn't as easy for Iwaizumi. He promised he'd be there despite that, after all. He'd wait as long as it took.

Oikawa wouldn't have to wait long.

"I love you." It was sure and steady, though Iwaizumi felt like the safety net had been ripped from underneath the trapeze he'd been so carefully treading on. Oikawa's obvious perplexity had Iwaizumi's insides churning. But then he smiled, and it was all Iwaizumi could think about.

"Mhm! Me too," Oikawa replied, kissing Iwaizumi until boldness took them both, and they'd filled the morning with each other.