Disclaimer: I do NOT own any Marvel characters or any thing related to the Marvel universe. I only own my OC Cassandra Stark. The amusement park is real, and I do not own that either!

AU where Pietro obviously doesn't die!

Hi, guys! So this is just a oneshot I decided to make because well, I love Aaron Taylor Johnson as Quicksilver and I'm on summer vacation so why not haha. Hope you guys enjoy it! :) Feel free to review and let me know how you guys like it!

"PIETRO MAXIMOFF!" I shouted as I ran down the stairs of the new Avengers base. I breathed heavily, my face red from frustration. Rhodey, Vision, Sam, Wanda, Steve, and Nat were all startled from my sudden outburst, but Pietro was not surprised as he continued to watch TV, remaining unfazed by my anger. I stormed over to him, my ponytail swishing around, ready to whack anyone in the face. Taking a firm stance in front of him, I held out my hand. "Give me my phone back," I demanded. Once the reason for my anger was revealed, the rest of the team rolled their eyes and went back to what they were doing.

"Here we go again…" I heard Nat mutter.

"No, I am watching." Pietro replied, his Sokovian accent thick with a hint of annoyance in his voice. I snarled, my frustration increasing each second. I narrowed my chocolate brown eyes and stepped closer to where Pietro was sitting.

Allow me to introduce myself. My name is Cassandra Stark, but you can also call me Cass. Yes, Stark; I am unfortunately the younger sister to Tony Stark. You might be asking me why I'm not with my brother at home and why I'm instead with the Avengers Initiative, and I'll tell you why. While my brother is away, the Avengers need someone who can be a hands-on person with all the tech and equipment at this new base. While Tony has JARVIS, I have FRIDAY. FRIDAY helps me here at the base, but operating the base isn't the only thing I'm capable of. I like to invent things like my brother, but I like keeping to myself.

"You guys are always fighting," Wanda noted, interrupting my glaring contest with Pietro. "Just like an old married couple." I scrunched up my face in disgust while Pietro fake-gagged. I knew Pietro wasn't going to give my phone back any time soon, so I sighed and began trudging to the lab Tony had specifically made for me so I could be even more of a "genius."

I shouted at Pietro, "When you're ready to give me my phone back, you know where to find me." Entering my lab, I wondered what I should work on first. "Hmm, maybe I should work on that matter teleporter…" I adjusted my glasses and sat down at my desk, fiddling with the device I started working on a few days ago. We really hadn't had any missions yet; it looks like we've been having a good break, for now. The matter teleporter I was working on would help transport things from one place to another in the blink of an eye. I wanted to build this to transport huge things like the Quinjet and other aircrafts, so the Avengers can get somewhere even quicker. I turned on the switches, and the two teleporters next to each other glowed a hazy yellow. I threw an apple in one of the teleporters and waited. "Come on…" I urged, biting my bottom lip. I heard something from the second teleporter, and I gasped in surprise as the apple flew out of the second teleporter. I sighed in disappointment though when the apple came out burnt. "UGH, STUPID TELEPORTER!" I yelled out as I buried my head in my hands.

All of a sudden, I felt a huge breeze of wind pass through behind me. I turned around and saw nothing, but when I turned back to my teleporter, I saw Pietro poking at different parts of it. He tossed me my phone with one hand, and I barely caught it. "What is this? Another one of your toys?" Pietro questioned, the smirk on his face growing as he saw my fists clench tighter and tighter. I placed my phone inside my jeans pocket and then crossed my arms.

"Don't. Touch. My. Stuff." I stated. Noticing I was furious, Pietro placed his hands up in defense and then stepped closer to me. Still sitting down, I looked up at him. For a few moments, we were just staring at each other in silence. I hadn't really noticed it, but his eyes were a really pretty shade of blue. *Wait, what the hell am I doing?* I abruptly stood up and pointed at the door. "Leave, please. I have things to do," I muttered silently, a sudden nervousness arriving in the pit of my stomach. I began to straighten my already straightened black v-neck. Pietro must have noticed my uncomfortable status as he placed his hand on my forehead.

"Are you all right? You seem…sick," Pietro asked with concern in his voice, something that was rare for him to feel towards me. Feeling myself turn red, I pushed his hand away and rolled my eyes.

"I'm fine. Now go, please." I asked. I turned Pietro around and began pushing him out of my lab. *His muscles are really toned, wait. UGH STOP THINKING THAT* I mentally slapped myself as Pietro left my lab completely. When the door shut, I stayed still for a few seconds, wondering what the heck came over me. The idea of liking Pietro was thrown away the second it popped into my head. "No way, Pietro is a womanizing little shit. I'm not going to deal with this, I'm only 19…" I mumbled as I walked back to my teleporter. Truth be told, I did find Pietro attractive, but then again he has women falling for Quicksilver left and right. Hearing the door open, I shouted, "I told you to leave me al-oh. Hey, Wanda!" Wanda raised her eyebrow at my initial shouting but nodded as I greeted her. "What's up?"

Wanda smiled and placed her hand on my shoulder. "You seem…erm, how do you Americans put it…pissy?" I laughed and shook my head.

"I'm not pissy, I'm just…stressed out," I reassured my close friend. Ever since Wanda and Pietro joined us, I've really gotten closer to Wanda. She and I tell each other everything from concerns to random facts.

Wanda offered, "Do you want to go out tomorrow? We can go to Enchanted Forest Water Safari and relax. I asked Steve and Natasha already, and they said we could." I gave Wanda a small smile.

"Wanda, I appreciate the offer, but I have to work on m—"

"Please, Cass? We both know you need a break from working. Even if we're not fighting, you are still working. You are an amazing inventor, and you help a lot of people, but you have to help yourself too," Wanda commented. She placed her other hand on my other shoulder and used her puppy-dog eyes.

I laughed and nodded. "First of all, I am not amazing. I just do what I do. And…okay, why not." In reality, I was actually very excited to go to the water park. It had been a while since I had some actual fun and going with Wanda was going to make it even more fun.

"Great!" Wanda exclaimed. "Okay, I'll leave you now." Wanda ran out of the room quite quickly, and I laughed at her enthusiasm. I clasped my hands and yawned, figuring it was time for me to go to sleep. I checked the time on my phone. *11:00? Hm...okay I'll sleep*

*3rd POV: Night time, Pietro's Room*

"Come on, Pietro, please! You know we haven't really gone out much to explore New York. This water park is going to be amazing. We can have our sibling bonding time, yes?" Wanda pleaded with her brother, attempting to use her puppy dog eyes to heighten the effect.

Pietro sighed and ran a hand through his hair and looked at his sister. "All right, all right. Maybe I can flirt with some American girls there." Wanda rolled her eyes but smiled nonetheless.

"Great! I will see you tomorrow!" Wanda hugged her brother and raced out of his room. Pietro chuckled at his sister's energy and took off his shirt so he could sleep comfortably.

"She's weird…"

*3rd POV: Avengers Lounge Room*

"You think this will work, Mr. Rhodes?"

"Of course it will, Wanda. Cass has always wanted to go to an amusement park for a date."

"But she doesn't know this is a date, Rhodes," Nat commented.

Steve sighed, "Those two need to get along. This is going to be a perfect opportunity."

"Not only that. They have to realize they are what you humans call 'in love' with each other," Vision remarked.

Sam pointed out, "How are we going to get them to leave the base at the same time without either of them being suspicious?"

Nat smirked and answered, "Leave that to me."

*Cassandra's POV: Next Morning*

"What to wear…." I pondered as I looked through my walk-in closet. I had just finished showering and I was in a bath robe. I let my brown hair air-dry, and I finally settled on a simple pair of mid-thigh jean shorts and a black Mickey Mouse tank top. I also threw on a pair of black flip flops, and I grabbed my black drawstring bag on the way out of my room. As I made my way down the stairs (our bedrooms were only on the third floor), I took out my brush from my bag and brushed my hair. "Morning, everyone!" I exclaimed happily. Everyone was situated somewhere in the Lounge Room, eating their different versions of breakfast. Everyone greeted me back, and I proceeded to the kitchen where I could smell Rhodey cooking bacon and eggs. I grabbed a plate and filled a mug with coffee. Rhodey placed some bacon, eggs, and toast on my plate.

I didn't bother to sit down as I quickly downed my breakfast and washed my dishes. "Cass, come here." Nat called. I walked over to her location by the bar, and I caught Pietro staring at me as I passed him. Once I got to Nat, she informed, "Before you go with Wanda to the water park, I need you to go to Mike's Gym Store and check up on our order for punching bags. I just need to confirm when they're going to arrive because I have other errands I need to run right now. I already told Wanda, so you can just go on ahead." I nodded my head and made eye contact with Wanda. She nodded.

In my mind Wanda explained, "I'll get a cab, do not worry about me. I still have to get dressed anyways."

I got in the elevator, went down to the lobby, and hailed a cab. "Where to, Miss Stark?" the cab driver asked, instantly recognizing who I was.

"Mike's Gym Store, please! I have to make a quick stop and then I have to get to Enchanted Forest," I explained. The driver drove me over to the gym store, and I did what Nat told me to do. Once I got back inside the cab, I texted Nat the arrival date of our order. The driver then drove me over to the drop-off lot of the water park, and I handed him the money owed. "Have a nice day!" I exclaimed at the driver as I began walking towards the entrance.

"Where are you?" – I texted Wanda.

"Meet me by the bush trimmed like a dolphin!"

Once I got to the dolphin bush, I was shocked to see who was there. "Pietro!?" I exclaimed. Pietro turned around and looked at me in surprise. He was dressed in khaki shorts and a white, fitted t-shirt that showed off his muscles well. "What are you doing here?"

"Wanda and I were going to go to this water park. What are you doing here?" It took me a while to understand what was going on, and then it hit me.

"Oh my gosh…" I muttered. I then let out a huge laugh, causing Pietro to stare at me weirdly. "She set us up! In fact, I'm pretty sure they all did," I commented. Pietro was still confused, and I facepalmed. "The team wants us to hang out together, but honestly, I don't know why they would put us together. We fight all the time."

Pietro retorted, "I wonder why." He and I stood there glaring at each other before Pietro suddenly grabbed my hand and started pulling me towards the line to buy tickets. "We might as well have fun," Pietro suggested upon seeing my shocked reaction of him pulling me. He smirked at my reaction. I looked down, feeling the stares of everyone else around us.

"Isn't that Quicksilver and Cassandra Stark?"

"OMG, are they dating?"

"Aaaah they look so adorable, I ship it!"

I felt my blush deepening as Pietro and I bought our tickets and went through the security check. Once we got into the actual park, he and I looked at the park map. "Where should we go first?" I asked. There was no reply, and I looked up to see Pietro staring at some girls in booty shorts not far from us. They were clearly checking him out too, and I rolled my eyes and walked ahead of him. Pietro caught up to me in less than a second. "You decide where to go," I commanded as I took out my phone and began to check all the details on my transporter for any areas of improvement. In the blink of an eye, Pietro took away my phone and bag. "W-what. HEY!" I shouted at Pietro, who now stood in front of me. He crossed his arms and shook his head.

"No phone. No work. I put our stuff in a locker, so we can have some fun. Let's go now," Pietro stated as he and I climbed stairs to get to the line for a water slide.

"Can I have my phone back?"

"No, shrimp."

"Don't call me shrimp, you…you…loser!"

Pietro looked irritated. "You have to learn to have some fun. Relax once in a while," he advised. "Besides, you can't leave me. I won't be able to find you easily since you're so small." I stared up at him, which was a normal thing for me to do considering I was 5'1."

"You're an idiot," I said while glaring at him.

Pietro shot back, "Prick" I punched him in the arm. He laughed it off and placed his arm around my shoulders. I was going to remove his arm from my shoulders, but the slide operator told us it was our turn. The ride was called the Rondaxe Run, and it was a double tube water slide ride. The operator was quick to place us in, and unfortunately, I had to sit in front of Pietro. To make more space, Pietro placed his legs on either sides of my waist. The ride started so abruptly that I didn't have time to hold on to the handles and instead leaned back into Pietro's chest. I screamed so loud when I was immediately drenched in water from both sides of the slide. Pietro wrapped his muscular arms around me and laughed at the rush of the ride. Once we got to the bottom of the slide, we stepped off and laughed on our way to another ride.

"That was amazing!" I gushed and shook Pietro's arms in excitement. He gave a small laugh and stared at me. "What? Is there something on my face? Stop staring at me, you speedy jerk!" I pushed the wet bangs off of my glasses and felt if there was anything on my face and ponytail.

"There is nothing. I just…" Pietro paused. I raised my eyebrow; he looked annoyed. "It is nothing. Nevermind. Let's go there." Pietro pointed to the Safari River Expeditions, where you basically sit on a tube and let the "river" float you around the path. *No way. He doesn't like me. It's…It's not possible* Pietro took off his shirt and stuffed it in his shorts pocket. I cursed myself as I found myself staring at his abs and muscles. I knew other girls were staring at him, but I shook my head and simply glared at the ground. The two of us got on separate tubes and floated next to each other. We sat there in silence, enjoying the calm and cool ride.

"Hey, after this, let's…" I stopped when I couldn't find his tube next to me. I looked around and found him a little ahead. He was in a conversation with a woman in a tube next to him. I rolled my eyes and felt a small pang inside. I watched the woman laugh as Pietro and she had a small water fight. I took in a deep breath and looked further ahead of them. *Good, we're almost done…* I hopped off my tube and into the water. Pulling my tube along the water, I made my way back to where we started, making sure to go between Pietro and the woman. I returned my tube to the guy in charge and waited for Pietro. Although when I turned around, he was already standing in front of me.

"Are you okay?" Pietro asked. He grabbed my arm, but I was able to easily slip out of his grip because we had just gotten out of the water.

"Fine. I have to go to the bathroom," I stated. I speedwalked over to the nearest bathroom with Pietro probably following behind me. When I got in there, I locked myself in a stall and slapped myself. *Why are you jealous? It's not like you have feelings for him, Cassandra Stark. Get yourself together. He is a womanizer, and you will not be one of his toys.* It was not until I went out of the stall did I realize how cold I was with my damp clothes on. "I'll just get my towel in my bag that…Pietro left in a locker…and I have no idea where that locker is," I sighed. As if he read my thoughts, Pietro was waiting outside the bathroom with a towel around his neck and another in his hand. His blonde-brown hair was still damp. I took the towel from him without speaking and wrapped it around my body.

"Are you hungry yet?"

"Oh, I thought you already went on a date with blondie over there," I remarked, jabbing my thumb in the direction of the Safari River Expedition. Pietro spun me around and held me by the shoulders. He peered into my eyes and smirked.

"Cassandra Stark, are you jealous?"

I stared at him in shock. "Jealous? No! Pbft, of course not! If anything, she'll rid me of you." Pietro didn't reply and instead continued to stare in my eyes. I suddenly started feeling embarrassed and leaned back. I poked his chest and pushed him back. "Yes, I'm hungry. Can you go grab some money out of my wallet so we can eat?" Pietro smirked and in a flash, he was back with…his wallet. "I said-"

"You already paid for ticket. I'll pay for food."

"Dick." Pietro held his smirk, and we walked to a place called Crossroads Eatery. We ordered nachos and sodas, and we were immediately handed our food. We sat down at a nearby table and began to eat our food. I refused to look at Pietro, my mind and heart still confused on how to feel. I felt Pietro's foot hit mine, and I looked up. He didn't seem to notice as he continued to eat his food. It was at this moment that I slowly began to accept that I had feelings for Pietro Maximoff. I fell for the playboy, the exact thing I told myself I wouldn't do when I first met him. *He's so handsome...* Once we finished, Pietro and I walked around the park to let our food digest.

"So…" I started. Pietro looked at me. "You haven't flirted with a girl for more than an hour, are you feeling well?" Pietro smirked.

"I stopped doing it. I think you became jealous enough for today."

"I am not jealous!" I exclaimed. I felt other people's eyes on us, so I decided to stop before we could make a scene. "Forget it, we are not having this conversation," I mumbled. I began to walk away, but Pietro grabbed my arm. "Let go of me, Pietro. We're causing a scene." Pietro let go, but I felt a blur of wind come and go. I looked at him and saw him carrying all our stuff that he placed in the locker. I watched him dart his eyes around, and he grabbed me and zoomed over to the line of the ferris wheel, one of the shortest lines. I clutched onto his shirt tightly, trying to catch my breath. "What was that for?" I asked between breaths. Pietro stayed silent as we moved further up the line. Once we got into the ferris wheel and sat across from each other, Pietro let out an annoyed sigh.

"What is wrong with you?" Pietro asked. I stared at him flabbergasted.

"What's wrong with me? What's wrong with you? You just used your powers while I was with you and the last time you did that, I threw up multiple times!" I yelled. I could tell Pietro struggled to keep calm because he was repeatedly clenching and unclenching his fists. I took in a deep breath as the ferris wheel continued to move.

Pietro listed, "Not being able to look at me? Getting jealous when I was talking to that woman? Acting weird? Cass, what is wrong with you?" I scoffed.

"As if you don't know already. Besides, why do you care? It's not like you've ever cared before. All you do is flirt and act like a teenager even if you're a full grown man," I commented, crossing my arms and looking away. "Unlike you, I've always cared. Ever since Fury and Tony asked me to come to Sokovia to help with the evacuation of civilians and I saw you for the first time, I cared. I cared when I saw you get hit with those bullets. I cared when Helen placed you in the Cradle, and I cared when I had to watch you die and come back to life from a miracle. I started having feelings for you, but then I remember Wanda telling me how you would flirt with all the women in Sokovia and sleep with different women when you were drunk. I didn't want to be another one of your play things. I love you. I-" I stopped talking, mainly because too many tears had streamed down my face.

Pietro placed his lips on mine, and I widened my eyes. I tried to resist, but Pietro pushed me against the passenger car, so I couldn't move. I kissed back and parted my lips, allowing Pietro to slide his tongue in and deepen the kiss. I hooked my arms around his neck, and Pietro slid his arms around my waist and sat down next to me. After what seemed like forever, we pulled apart. The two of us stayed there panting from the lack of oxygen.

"Cassie…" Pietro wiped my tears away. "I'm sorry. I am sorry for making you go through this pain. I flirted with women back in Sokovia because I was immature and had nothing better to do. They helped the pain of my parents and past go away. I only flirted with the woman today to make you jealous and I was not thinking. I was scared, forgive me. I love you, but I was afraid. I was afraid because I knew I was not supposed to be alive. I should have died, but I was saved. I was afraid of dying again, so I didn't want you and I to love each other only to watch you be in pain as I die again. Cassandra Stark, I fell in love with you the first moment I saw you...I know it's cheesy, but is true."

"Pietro -chuckle- that is pretty cheesy but...you're not going to die again, Pietro. I'll make sure of it. We will all make sure of it. You're safe now. You are not going to die," I stated with a smile as I placed my hand on his cheek. Pietro placed his hand on top of mine.

"But Cassandra, how are you so-"

"Oh, just shut up and kiss me." I placed my lips back on Pietro's and I swore I heard fireworks.