A/N Requested by Barbemeli + just_michaela123

Peter was hungry. Well, he was always hungry, with his fast metabolism and all, but today he was extra hungry. 

Why was this? Honestly, Peter didn't know, but perhaps it had something to do with the fact he had just ran all the way from school, had skipped breakfast, forgot his lunch and had a fitness test in sport class that day. 

Shrugging it off, Peter raided the fridge, biting into an apple and holding a plate of leftovers in his other hand. He slipped himself onto the counter and swung his legs, munching happily on his food as he awaited his family to arrive home from either work or the lab. 

Natasha, Sam and Clint were training new agents in shield that day, and he assumed Bucky and Steve were probably out on a hike or trying out things that didn't exist back in the day. 

Tony and Bruce were probably in the lab, and Wanda and Vision has mentioned going out for ice cream earlier that morning. Thor was back in Asgard, but if he remembered correctly, he would be back today. 

The thought brought a smile to Peter's face, throwing the apple core into the bin nearby, grinning wider when it turned out to be a perfect shot. 

Peter slid off the counter, glancing around for a cup of water, his throat dry with thirst. 

He immediately spotted a cup of clear liquid which he assumed was water, and decided that nobody would miss it. 

He swallowed it all at once and gagged at the taste; what horrible water. In fact, it tasted nothing like water- it was thicker, with a bitter taste and the aftertaste was like drinking orange juice after you've brushed your teeth. 

He began to worry that he'd just drank someone's pee- but someone who had drank a lot of water or something- when he began to shrink. 

"Hey Peter Friday said you were home, have you seen where I put my lab experime- where are you?" Tony cut himself off, glancing around the very empty looking kitchen, where there was a half eaten plate of leftover pizza, along with an empty cup on the counter. 

Peter's bag was by the door, right in the way like always, but Peter himself was nowhere to be seen. 

Frowning, Tony's eyes went to the ceiling, where Peter normally hid in order to scare them. However, the young spider was not there. 

"Friday where's Peter?"

"Peter is in the kitchen sir." 

Was Friday malfunctioning? Tony thought. "No he isn't," he told her. 

"I'd advise you look behind the counter sir." 

Tony walked around the kitchen island counter and his heart flipped at the sight- there was a small, six month old looking baby, laying on the ground surrounded by... Peter's clothes? 

"Peter come out this isn't funny, where'd you get the baby from?" He called out, looking around. 

There was no answer, his voice echoing around the empty room. 

"Friday where is Peter?" 

"He is right in front of you sir." 

"No he isn't, Peter's fifteen." 

"Playing footage of: five minutes ago." Friday projected the security footage of only five minutes ago, showing Peter bound into the room like an overexcited puppy, dumping his bag on the floor by the door and running over to the fridge. 

He pulled out an apple and a plate of leftover pizza, munching on his food and sitting on the counter despite the amount of times Tony had told him not to (tables are for eating off not sitting on) then threw his apple core into the bin. 

Tony watched as he noticed the 'water', gagged, then frowned at the cup, as though wondering what he had just drank. Seconds later, Tony watched as he shrank into the small child, laying on the ground before him. 

Tony looked down at Peter, who stared back up with his big doe eyes, which began to water. 

Already sensing what was going to happen, Tony backed away. "No no no no, don't cry! Friday help!" 

"I suggest you pick Peter up sir." Friday told him, as Peter's lip trembled and tears dropped down his small, chubby cheeks. 

Taking Friday's advice, Tony bent down and picked Peter up, holding him up at arms length. 

"Friday call Pepper." Tony called as Peter began to wail loudly. 

"Calling Pepper Potts." 

"Hey Tony I was just about to call you about that interview you're doing tonight-"

"Cancel it! We have an emergency!"

"Emergency? What do you mean? Is that crying I hear-"

"Peter accidentally drank one of my experiments and now he's a baby and I don't know what to do Pepper help?!" 

There was silence for a few seconds. 

"I'm on my way." 

Pepper hung up, causing Tony to swear. Peter started crying harder, wriggling in Tony's grip. 

"Do you want to go down? Huh? Here we go." Tony slowly placed Peter down on the mat, and Peter's crying quitened a little, his teary brown eyes looking around the room, taking everything in. 

Only ten minutes later, Pepper arrived, one arm holding a couple of bags filled with everything a baby would need. 

"So it's true? Peter's a baby?" She asked, walking over and putting down the bags. Peter turned and looked up at her with his miserable, teary eyes. 

Pepper's eyes softened as she knelt on the ground beside him, smiling in order to make herself less intimidating to the little boy. She dug out a nappy (or diaper, whatever you call it) and put it on him before slowly picking him up, resting his head on her shoulder and bouncing him up and down ever so slightly. 

Tony watched as she did so, like a natural mother. Peter already seemed to be dozing off on her shoulder. 

"Can this be reversed?" Pepper whispered as Peter's breathing grew heavier and louder. 

"He should turn back once it's gone through his system but that could take up to two days." Tony whispered back. 

"So we need to take care of him like this for two days?!" Pepper whisper shouted. "How did this even happen?"

"I left my lab experiment out on the kitchen counter. He must've thought it was water." 

"Anthony Howard Stark!" 

"I'm sorry! It won't happen again!" 

"It better not because I'll have your head if it does." 

"So am I off the hook?" Tony asked, smirking. 

"Of course not, you're going to need to do a lot to make it up to him when he's back to normal." 

"Isn't taking care of him enough though?" 

Pepper sent him a stern glare. 

"Alright alright, I'll make it up to him I promise." 

Sighing, Pepper left the room, Peter in her arms, heading towards his bedroom. 

*** 

"Tony I have to go I'm CEO, I can't just not go to this very important meeting." 

"But Pepper! It's halfway across the world, you can't just leave me with him! I don't know how to take care of babies!" 

"Feed him, wash him, make up sleep, hold him, comfort him, and anything else you can think of that you do to babies. It's simple, and you'll learn. The other's will be back soon and I'm sure they'd be happy to help." 

"But Pepp!" 

"No buts. Oh look, he's awake." Pepper pushed into Peter's room, right beside where the two had been arguing, mainly about how Pepper had to leave that night. 

Peter was sitting up in the middle of his bed where Pepper had put him down, crying and lifting his arms when Pepper grew closer to him. Tony had to admit, he was cute. 

"Shhh," Pepper whispered, Peter immediately stopping crying when he was safe in her arms. "How bout we go to the lounge room, huh?" 

She carried Peter into the lounge room, jerking her head in a motion to tell Tony to come with her. 

Tony followed her, and all of a sudden Peter was in his arms. 

"Pepper! What are you doing?!" He hissed, starting to move Peter away from him, but Pepper pushed him in closer, adjusting Tony's hold to make it more comfortable for Peter. 

Peter, who didn't particularly like Tony, frowned, scrunching his features and looking adorably grumpy. Pepper laughed slightly at his expression, moving away and heading towards the elevator. 

"I'm going to go pack. Good luck." 

"What? Pepper no- don't leave me- what-"

The doors of the elevator closed, and Tony leant against the back of the couch, sighing and looking at Peter, who looked back, his face surprisingly suspicious as he eyed Tony. 

"Oh don't look at me like that, it was your fault you drank the experiment." 

***

Clint, Sam and Natasha arrived home, exhausted from all the physical work they had done all day. They were about to collapse onto the couches when they saw Tony, sitting on the couch, leaning back with a baby on his stomach, which was tugging on his hair and slapping his face. 

"Ow- Yes that's my hair, well done, now let go- ow no, don't pull harder- stop-" 

"What the hell?!" Sam said loudly, catching the attention of both the baby and Tony, the baby looking afraid, it's lip trembling, and Tony looking relieved. 

"Oh thank god you guys are back! Peter drank my lab experiment by accident and now he's a baby! Clint, here you go." Tony stood up and dumped Peter in Clint's arms. 

"I- what?" Clint said, easily holding Peter correctly and resting his head on his shoulder, patting Peter's back gently and hushing him until he stopped crying. 

"I left a lab experiment on the kitchen and he must've thought it was water and drank it." Tony sighed, rubbing his face. "You can watch the footage if you like." 

"Yes please," Sam said, everyone sitting on the couch, Natasha playing with Peter, a small smile on her face. She had always loved kids, that's why it hurt her so much to not be able to have children of her own. 

Clint, Natasha and Sam watched in shock at what happened, eyes turning to the little boy that was shaking a small toy, eyes wide in amazement. 

"That's- Peter?" Sam said slowly. 

***

Steve, Bucky, Wanda and Vision arrived back at the tower, having had a great day going around New York, eating ice cream and looking at the new things Steve and Bucky hadn't even known existed, stopping by the cinema and watching a horror movie that made Vision cling to Wanda in fear, while Steve jumped at every jump scare and clutched Bucky's metal arm. 

There, in the lounge, was Clint, Sam, Natasha and Tony, along with a small baby and Bruce, who was writing observations into a notepad. 

"What- Why is Peter a baby?" Wanda asked. 

Clint frowned. "How'd you know?" 

Wanda didn't answer, causing Natasha to roll her eyes lightheartedly, bouncing a very upset looking Peter. 

"You need to stop reading people's minds Wanda." She drawled. 

"I'm sorry, it's hard sometimes. He's hungry by the way." 

"That's why he was crying!" Sam said, and Bruce scribbled something out of his notepad, face pinkening. 

"What did you think it was?" Wanda scoffed, seemingly the only one other than Vision to recover from the fact that Peter was now a baby. Vision was already standing in front of Peter, examining him with interest. 

"...pain from the experiment..." Bruce mumbled, pulling out the piece of paper from the notepad and scrunching it up in one hand, stuffing it into his pocket. 

"Wait, experiment? You guys experimented on Peter-" Steve started scolding them, which made them have to explain what had happened, and that Peter would be perfectly fine in two days or so. 

Bucky, meanwhile, wordlessly found the baby food Pepper had bought for him. He mashed up the banana with a fork, then grabbed a teaspoon and plucked Peter out of Vision's hands, resting Peter on his knee as he started feeding him. 

Peter immediately stopped his crying, trying to direct his head towards the spoon, mouth open. He wasn't very good at it, and once it was in his mouth he sucked on the banana, opening his mouth again the moment Bucky had made another teaspoon full, banana slipping out of his mouth and onto his chest. 

Bucky chuckled, catching the attention of the others, who only just seemed to notice him feeding Peter. 

"My couch!" Tony whined as banana fell onto the white couch. 

Clint sent him a sympathetic look. "That's always the worst part mate," he said. "You can't have anything nice, they'll mess it up for you. One time when Lila was a baby, she puked all over my shield suit. I didn't have time to wash it, I was needed that day, so it was really embarrassing to turn up with a massive damp patch on my suit, with chunks of white milk on it." 

Sam sent him a disgusted look. "Nobody needed to hear that Barton." 

"Oh that's not the worst of it, Nathaniel got a stomach bug once and sh*t his pants really bad-"

"Alright Alright that's enough!"

"-and it got everywhere-"

"Clint-"

"It stunk so bad. Then Cooper couldn't handle the smell and vomited-"

"BARTON." 

"-which got all over my socks and shoes-"

"Clint I swear to god!"

****

They had finally gotten Peter to bed after feeding him and about half an hour of walking him around the house in Steve's arms. 

Tony was glad for the absence of noise, everyone eating the dinner that Natasha had ordered, since nobody could be bothered cooking. 

There was a repeat of everything the next day, Peter crying, eating, pooping (poor Clint got him every time that happened) and sleeping. He would play too, crawling on the ceiling at one point and scaring the living daylights out of Tony (who was turning into a stressed dad) and Steve (who was turning into a stressed mum). 

They ended up having Tony sit on Steve's shoulders and try to get Peter down, Thor watching joyously from nearby, fully aware he could just hand Peter the hammer and watch him come straight to the floor (assuming he wasn't worthy, but secretly, Peter knew he was.)

After that Tony tumbled to the ground, bringing Steve and Peter with him, but Peter ended up being perfectly fine, sitting on Steve's chest and giggling. 

Thor had to hold Peter after that, for they didn't trust Peter to go crawling by himself. He was swapped between everyone with super strength- Steve, Thor and Bucky- And occasionally Natasha (though not often, because she kept handing him knives or daggers which he immediately thought to be food) or Clint (the official nappy changer). 

They were all really happy when Peter turned back to normal that night, but unfortunately, Peter couldn't remember anything. 

"What? What happened?" Peter asked, looking around in confusion. 

"What's the last thing you remember?" Bruce asked kindly, who was kneeling beside where Peter had fallen asleep. 

"I- I don't know... nothing specific I guess." 

Bruce turned to the others. "His brain's gone through a lot of trauma, so it's understandable that he can't remember anything."

"Trauma? What happened?"Peter asked, eyebrows scrunched in confusion. 

"Uh-" Everyone exchanged looks, unsure whether or not they should tell Peter. 

It seemed they didn't get a choice, for Thor had already started informing Peter of what had happened, explains everything in elaborate detail and not realising that Peter might end up embarrassed. 

"So- I turned into a baby? But that's impossible."

"Not really kiddo, but it takes a lot of combinations of chemicals and mutating of cells to revert back to several years younger. It was supposed to make people look younger, but I guess you're so young already, and it was rather highly concentrated..." 

"Oh... who are you all by the way?" 

Oh boy, thought Tony. This was going to be a lot of explaining. 

**** 

Peter sat on his bed, reading through his old journal, which he wrote everything down in. Apparently he was a crime fighting vigilante, which didn't make much sense to Peter (climbing up walls?? Must've been some good technology in that suit). 

Peter heard his phone buzz and grabbed it with his hand, looking at the new message from someone called Ned. Pepper had told him that Ned was his best friend the first time he got a message from him, and Peter replied to Ned's message explaining that he had lost his memory. Now Ned was messaging him once again, much later, asking if his memory was back yet. 

PeterParkour!: 

<not yet, sorry

GuYInTheChAiR: 

<Tis ok

Peter attempted to drop his phone back onto his bed, but the phone, strangely enough, stuck to his hand. 

"What the hell?" He muttered, shaking his hand and trying to get it to come off, only to accidentally fling it across the room. Peter winced when he picked it up later with a pair of chopsticks, looking at the thin crack across the top. 

He placed the phone down, then looked at his hands, wondering if he could try climbing the walls like it said he did in his journal. 

It turns out he could, but... he couldn't get down. 

"Peter! Dinner time!" Bucky called, heading into Peter's bedroom without knocking- a habit of his. He frowned when he didn't see Peter, then his eyes trailed up to the ceiling, where Peter clung to the ceiling, looking severely stressed. 

"Peter?" He asked, confused. 

"I-I'm stuck. Please help."

"Can't you just let go?"

"I'VE TRIED." Peter said, trying to remove his hands from the ceiling. 

"Uh, okay, do you uh, want me to get a broom or something?" 

"I DON'T KNOW." Peter replied loudly, obviously stressing. 

Bucky left the room to grab a broom, but the second he took two steps away, he heard a loud crashing noise. 

He rushed back inside, and Peter was on the ground again, clutching his head. 

"You got down then?" Bucky said, chuckling. 

"And my memories. Ah f*ck, the memories. This is so embarrassing." 

"Language!" Steve's voice was heard faintly in the distance, and Bucky and Peter both wondered how exactly he had heard them from the other side of the floor. 

"Let's go get dinner, they won't tease you about it, and if they do, I'll kill them. I also think Stark owes you a bunch of favours now," Bucky said, smirking. 

A wide grin appeared on Peter's face as he followed Bucky out of his room, still rubbing his head. 

"Do you think he'll get me ice cream? And maybe a new phone since I smashed mine?" 

"You smashed your phone?" 

"What. No. You heard nothing."

Bucky laughed, shaking his head. "I'm sure he'll buy you everything you want Pete, but maybe don't drink lab experiments next time." 

"It wasn't my fault!"