A/N: dedicated to ChristielJackson and im a terrible person for taking ages to write this PLEASE FORGIVE ME MY LOVE

I played with some scientific instrument, fiddling it between my fingers.

"Are you two almost done?" I shouted behind my shoulder, groaning. With no answer, I took it upon myself to move deeper into Tony's lab.

"Tony, Bruce, when are-" I began, suddenly unable to speak. I instantly began to panic; a bright light had hit me, knocking me to the ground. A hot pain shot throughout my body, and when I opened my eyes, things seemed... bigger.

"Oh my god, Tony!!!" Bruce shouted. I furrowed my eyebrows, trying to stand. My knees felt weak, and with that, I fell back to the ground.

"Hey, have you gu- what the hell?!" A new voice yelled, staring down at me with confusion. Bucky. "Why is there a baby in here?"

A baby?

"Guys, whats going on?" I spoke, only my voice was young and high-pitched.

No. Way.

"Tony!!!!" I screamed, my shrill, childish voice echoing throughout the walls. I began to sob loudly, falling onto my back. What a sight that must have been; three year old me, throwing a temper tantrum.

Bucky sighed, scooping me up. I blushed, flailing my arms around. With no obvious avail, I sighed, crossing my chubby arms over my chest.

"What happened?" Bucky murmured, holding me against his warm chest, absentmindedly rocking me softly.

"Well, we playing around with super-soldier serum stuff, to test the aging process, and... well, I guess we screwed it up." Bruce explained.

"No shit!!" I squealed. Tony smirked.

"Now, that's no way a three year old should be speaking." He scolded me. I let out a whine, flipping him off.

"I swear on my life, Tony!! You're going to fix this, and when you do, I'm beating your ass!!"

Tony laughed, rolling his eyes. "Someone need's a nap."

I gasped, tears prickling my eyes. "Bucky!" I whimpered. Bucky sighed, smiling gently.

"Just figure it out, guys." Bucky chuckled, leading me out of the room. I looked up at him, gawking at Bucky's ridiculously handsome face that seemed to radiate even more under a babys' eyes.

"It's not funny." I mumbled as Bucky laughed, slapping a small hand on his firm chest.

"C'mon, it's a little funny. If it was me, you'd be bent over laughing." Bucky tried reasoning with me, melodic laughs sputtering from his lips.

I stifled a giggle, blushing in realization. "Ok, maybe." I admitted. "But I really don't want to be a three year old."

Bucky raised an eyebrow. "Why? Now I get to take care of you!"

I snorted, throwing my tiny head back with laughter. "Oh, what a joy." I teased.

"Hey, who's the one wearing diapers?"

"Actually, no one. Last I checked, I'm in a too-large sweater."

Bucky chuckled, nodding his head. He stopped at my room, setting me on my bed. Sadly, it was only the start of my long, agonizing journey.

---

After a week of Tony and Bruce slaving in the lab, they had finally found the cure. Of course, I didn't know that yet. Bucky had left me in his room (great "parenting" huh?) when Tony called him down. While he was gone, I smirked, spotting a black mass in the corner; and I knew exactly what it was.

With my small hands, I grabbed Bucky's mask and goggles, slipping it over my small face. I giggled as half of it slipped over my face, reaching up to hold it in place.

"Y/N, guess wh-" Bucky burst into the room, stopping mid-sentance. He let out a quick laugh, holding his stomach as he bent over laughing.

"God, you are too adorable." Bucky smiled softly, kneeling next to me. "Ready to not be a three year old?"

I pouted at his compliment, nodding. He scooped my up, grabbing a sweater and slipping over my head; the baby clothes Pepper had managed to find wouldn't stretch too well when I was back to normal.

Bucky set me down in my designated chair, allowing Tony to strap me in and hook me up to some machine.

"It'll hurt a bit." Tony advised me.

"Not as much as it'll hurt when I beat your ass." I mumbled. Bruce laughed, turning on the machine. A small, electric pain caused me to jump; other than that, I felt fine.

"There we go!!" Tony clapped, unhooking me from the machine. I furrowed my eyebrows.

"Thats it?" I mumbled. I felt a bit dizzy; along with feeling taller and all together bigger. I looked toward Bucky, flushing in crimson as he offered me a handsome smile. He sent me a thunbs-up.

I dusted my hands on my thighs, placing them on my hips with a content sigh. "Well, now that that's done and well..." I paused, turning to Tony. I marched over to him and slapped him across the face.

"Don't mess with that shit, you idiot!!" I screamed. Tony whined, holding his red cheek.

"Alright, alright, sorry.."

I huffed, a proud smile across my features. I turned to Bucky again, laughing shortly.

"Thanks for babysitting me."

"Well, now that you aren't a child, is now a good time to ask you on a date?" He winked. I mentally swooned, rolling my eyes and blushing nonetheless.

"Yeah, I'll go to dinner with you. But you gotta burp me afterwards." I teased, nudging his ribcage. Bucky laughed, pulling me into a hug, suddenly throwing me over his shoulder. He sarcastically patted me back like you would a baby, all the while, I was a blushing mess.

"C'mon!!" I whined, finally managing to push myself off of him. I smiled softly, patting his chest.

"Alright, let's go get some food." I chuckled, pulling on his hand.

"Can do, baby." He joked, but I had a feeling the nickname wasn't just because of my incident.