"Hey, guys! I'm home!" Peter shouted, walking out of the elevator and slamming his school bag onto the ground. He looked over his shoulder and realised that his family wasn't in the room.

"Hey, FRI. Where's dad and the rest?" Peter asked. "BPGP ( billionaire, playboy, genius, philanthropist) ( A/N: I didn't want to use tincan) is currently experimenting with Brucie Bear in the lab and the others have all gone for a SHIELD briefing." FRIDAY said.

Peter chuckled slightly at the nickname. He and Clint had hacked into FRI and changed everyone's name for an April fools prank, and it had just stuck around.

He walked over to the kitchen and made himself a sandwich - well - ten sandwiches. Growing spider babies needed to eat. He made a few sandwiches for Bruce and Tony too. Knowing them, they wouldn't have eaten or slept since they started.

He asked FRI to take him to Tony and Bruce and walked into his dad's private lab. "Hey! I bought sandwiches for the science bros." Peter shouted, but saw that the lab was empty.

"Huh." Peter shrugged, setting the plate down on the lab table.

He asked FRI to alert the two that he was in the lab and waited for them to come back. He quickly scarfed down all his sandwiches and then tried to find something to drink. He spotted the freezer that they kept in the lab, and walked towards it and opened the door.

Peter grabbed a bottle of brownish - black liquid, thinking that it was Coke, and took a big swig from it before setting it down on the table.

He grimaced at the taste and spat it out in surprise. This wasn't coke!

He quickly recapped the bottle and pushed it away in disgust before sitting back down. After a minute-much to Peter's horror-he could feel a warmth spreading through his lungs, making him feel tingly-the way you feel when you drink cough syrup during a bad cold.

All of a sudden, his entire body started quivering and his senses started buzzing and going haywire. He could feel something awful coursing through his body.

Peter felt dizzy and saw that everything around him had slowly started becoming big, making him startle. He then realised that he had become small, and started screaming.

By now Tony and Bruce had walked into the lab to see a five year old kid with brown, fluffy hair and big, brown doe eyes in clothes that were too large for him. He was scrunching his eyebrows and glaring at them, which made him look like an angry puppy. Tony silently started having a mini heart attack.

Bruce noticed the now half empty experiment and put two and two together. "He drank the experiment!" Bruce shouted.

"No 'hit 'erlock!" Peter said, pouting.

"Oh god! Oh god Oh god!" Tony shouted, nervous. "He did what - why did you do that Pete?" Tony asked, running a hand through his hair, frustrated.

"I thought it was Coke!" Peter said indignantly, but it sounded more like ' I 'ough it 'as 'oke!'.

"At least we know our experiment works..." Bruce said trying to look at the bright side. Tony rolled his eyes and hoisted kid-Peter onto his shoulder after he started tugging on Tony's pants and raising his arms in a 'pick me up!' gesture.

"At least I don't have to change his diapers." Tony shuddered "But I'm totally screwed if Pepper and the rest find out."

"C'mon Peter, let's find you some new clothes." Tony said, taking Peter out of the lab, instantly activating 'dad mode'. Bruce shook his head and followed.

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"Okay!" Tony announced, "You're all dressed -" he said, gesturing to the Iron Man footsie that he bought ( that's a wild story for another time ) "- and fed. Now all we need to do is figure out how to bring you back!" Tony said, clapping his hands together.

Peter just stared at him with his doe eyes. He had retained all his knowledge, much to Bruce and Tony's relief, but his behavior was that of an average six year old.

"Can we pwease pway, dad?" Peter asked adorably.

"Fine" Tony smiled, instantly melting at that. "What do you want to play?" Tony asked Peter.

"Lego's!" Peter shouted excitedly.

He quickly located the Lego's and went back to Peter. Bruce had left them long ago, trying to reverse the effects of their experiment.

The father and son duo sat cross legged on the floor and emptied the bucket of Lego's onto the ground. Peter instantly attacked it, and decided to sort everything by colour while Tony started playing with his phone.

After sometime, Peter shouted out "Dad!" Causing Tony to snap out of his reverie.

"Yes, Underoos?" Tony smiled at the easily excitable kid.

"Here." Peter said, thrusting something into his hands.

Tony looked at the figure and grinned. It was a Lego model of the Avengers and Pepper wearing the Iron Woman armor with mommy scrawled across it with a sharpie.

But that wasn't even the best part. Replacing Clint was Katniss Everdeen from the Hunger Games (A/N: She found love in a toastless place) and Steve was holding a dinner plate.

"Why is Uncle Steve holding a dinner plate kid?" Tony asked, laughing quietly.

"You s'oot him in ze legs cuz his shield is ze size of a dinner plate and he is ze idiot." Peter said, imitating a horrible German accent, causing Tony to roll on the floor laughing.

"Oh - that's precious!" Tony laughed.

"BPGP, Uncle Military is incoming, t-minus 5,4,3,2,1" FRI interrupted, perfectly finishing her countdown as Rhodey burst through the door.

"Hey, Tones - what the fu-" Rhodey shouted, seeing kid-Peter, but was interrupted by Tony covering Peter's ears.

"There's a kid here!" Tony said, berating Rhodey.

"That's exactly my point!" Rhodey shouted while kid- Peter muttered, "Big 'eter's said 'orse."

"Rhodey, meet Peter." Tony announced holding him up.

"Uh-Uh- I've met Peter and he's a twelve year old Tones, not six!" Rhodey said, utterly confused.

"I'm 'ifteen! Well, 'as 'ifteen!" Peter pouted.

Tony asked Peter to continue playing while he explained the situation to Rhodey.

"Ok!" Peter said happily, minding his own business. Tony ushered Rhodey into the hall and told him about the great blunder of Tony Stark, number 3000.

By the time he was finished, Rhodey didn't know whether he should laugh or scold his best friend. Tony was currently pleading with Rhodey to help him out as he didn't know a single thing about kids and he didn't want the rest of the team to know about this.

"Fine!" Rhodey complied, following Tony back to Peter.

However, Peter was nowhere to be found. "Peter!" Tony shouted "Underoos, where are you?" Tony said while searching around the room.

"Shit." Tony declared, wearing his best 'I'm so screwed' expression. "The tower is so big! How will I find him?" Tony asked Rhodey.

"Geez. If only there was an AI called FRIDAY that could see where exactly Peter is!" Rhodey smirked.

Tony had a mini epiphany and quickly asked FRI to locate Peter. "Peter is currently right here in this room" FRIDAY sassed "He's above your heads." Tony and Rhodey's eyes widened in surprise and stared at the ceiling while FRI told them that she was rolling her eyes at them.

"Looks like he found the bowl of candy" Tony muttered, trying to get Peter off the ceiling. "Come to daddy!" Tony cooed at the adorable kid, desperately trying to reason with Peter.

"Nuh-uh!" Peter declared, stuffing his face with the candy from the little bowl they kept, which was currently webbed up to the ceiling. It took a lot of coaxing and pleading, but Peter eventually crawled down.

Tony then tried to bathe Peter, on suggestion by Rhodey. Tony had to drag him kicking and screaming to the tub. After he outright refused to step into it, Tony had an idea.

"Be right back, kiddo." Tony said, shutting the bathroom door and immediately getting to work.

Tony opened the door after a minute and let Peter in. Peter smiled when he saw his red and blue bath tub filled with bath bombs and bubbles.

"Yay!" Peter shouted, instantly jumping into the bath.

Tony slumped against the door in relief, happy that he had finally figured kid-Peter out.
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Peter sat on the sofa, watching Star Wars and eating a bowl of ice-cream after blackmailing Tony into giving it to him. He smiled at the lightsaber Luke was currently wielding and said, "Dada 'ook! Glow 'ticks!"

"Big Peter would have died of a heart attack if he ever came to know that he called a lightsaber a glow stick." Tony laughed.

It was nearly nine' o clock by now, and Rhodey had long since retired to his flat. Bruce was still stuck in the lab with no news. Peter slowly started adorably rubbing his eyes.

"'Am sleepy" Peter drawled, crawling onto Tonys chest.

"So soon kid?" Tony chuckled, laying a comforting arm on him.

"Big Peter has not been 'eeping. 'ight'ares scary." Peter revealed, eyes already heavy.

Tony froze at that. "Big Peter isn't sleeping because if nightmares? About what are they?" Tony asked, scared to know the answer.

"Uhuum, a'out the 'ime a building fell on 'im" Peter asserted, causing Tony's eyes to bulge out.

"A building fell on you?" Tony asked.

"Yeah... 'ig 'eter has 'nxie... Anxiety attac's too!" Peter said, eyes finally shutting firmly, asleep.

Tony was shocked by the revelation. He knew first hand how bad a panic attack could be. He made a mental note to talk to Peter about this as Tony slowly started falling asleep too, unable to resist the adorable kid that was currently asleep on him.

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"Anthony Edward Stark!" Nat shouted, causing Tony to startle and fall of the couch. "What did you do to my spider baby!" She asked, ready to slam kick him.

"Hey! You guys are back!" Tony said nervously.

"You're lucky I didn't kill you in your sleep. Be thankful that Peter already told us what happened." Nat declared stepping aside to reveal Peter in Bucky's arms, sipping something from a cup which was held by Vision while he played with Bucky's hair. Steve was making pancakes for breakfast, Clint was making goofy faces, trying to make Peter laugh while Pepper and Wanda were cooing at Peter.

Tony smiled at the sight. Kid Peter had already wrapped everyone around his chubby little finger. 

"Breakfast is served!" Steve declared, slapping stacks of pancakes in front of everyone.

"Can I pwease have 'ipped cream?" Peter asked Steve shyly. In response, Steve unloaded an entire bottle of whipped cream onto Peter's plate.

"Yay! Your the best Uncle Steeb!" Peter declared, causing Clint to snort.

"So!" Wanda asked, smirking. "What did you guys do yesterday when we weren't there?"

"Well..." Tony took his time answering. "We had to get Peter to wear his kiddie cloths, eat, get off the ceiling, stop eating ice cream and candy, bathe him and get him to sleep. It was exhausting." Tony shuddered at the memory.

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Needless to say, by the end of the day, the tower was a complete mess. Clint and Peter had snuck into the vents and toilet papered everyone's rooms while Tony and Peter caused Dum-e to spontaneously combust. Nat and Peter had managed to destroy not one but five toasters and ovens trying to make toast. Steve and Bucky were the only responsible ones, feeding, cleaning and bathing Peter while the others had fun.

At around Nine pm, Bruce can out of the lab, looking like a vampire exposed to sunlight ( A/N: He was not sparkling! ). "Here" He said, slapping a bottle of pink liquid in front of Tony. "The cure." Bruce declared as though it was god. Nat took the bottle and cajoled Peter into drinking it.

They all patiently waited for Peter to return. Soon, the older Peter returned and ran away to put something on  that wasn't a six year old's.

"So..." He said, plopping onto the couch. "I'm never doing that again."

Clint rolled his eyes and said, "He shall'enth leaveth his worketh aroundeth anymore." causing everyone to sigh.

Someone really had to convince Loki to stop pretending that he was dead and remove the spell he cast on Clint, which caused him to speak only in Shakespearean English.

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"Oh my god! I called lightsabers glow sticks!"

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"Oh my god! You bathed me!"

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"Oh my god! I accidentally vomited on Uncle Bucky!" ( That had happened when Tony was asleep )

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"Oh my god! I told you about - about the building!"

"We need to talk, young man." said all the Avengers simultaneously

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A/N: Whew! That's one of the longest chapters I've written till date! It's 2:23 am here and I'm too tired to proof read. Please ignore the obvious mistakes. Shoutout to larbu3000    Strangerlosve  and Zach1275 ! I hope I got your usernames correct. Thanks for bringing this to 700+ reads! I larb you guys!

Goodbye!