Requested by simpforsoup: Y/N Stark and Peter are hanging out in the lab when they start messing with one of Bruce's gadgets. This gadget causes them both to pass out and they wake up having swapped bodies. The rest of the team are on a week-long mission and so they have to help each other figure it out, like when Y/N gets a period and Peter gets a boner. When the team returns, Bruce switches them back, and they share a 'thank god' moment that results in their first kiss.

*Please note: When Y/N and Peter switch bodies, I have kept their pronouns the same, so she/her for Y/N and he/him for Peter. This is not at all indicative of my news on trans people and pronouns, and this is not a welcome for people to be disrespectful about other people's pronouns and choices. Thank you, and enjoy :)*

I sat on my bed, my eyes on my homework as I tried to finish it. But I had to admit that I was growing increasingly bored. I puffed out and looked away from my laptop as I tried to figure out what I could do considering that the majority of the team weren't here. I was Tony Stark's daughter, and my dad had left just me and Peter in the Tower whilst he went on a week-long mission with the rest of the Avengers. And whilst hanging out with my best friend was far from a bad idea, I also tried to limit my time with him. I did that for the sole reason that I liked him as far more than just a friend, and I was terrified that one day, the truth would come out. But right now, there was nothing else to do apart from find my best friend and hang out with him.

"FRIDAY, where's Pete?" I asked as I stood from my bed and headed to my door.

"Mr Parker is in your father's lab, Miss Stark." The AI replied.

"Thank you kindly." I nodded to myself as I headed to the elevator and got in. I pressed the button for the lab, the glass box starting to move down as it took me to the lab of the Tower. Within seconds I got there, the doors opening to surely enough reveal Peter sitting at the bench with his eyes on his suit. He looked up at me as I wandered out of the elevator.

"Y/N, hey. You okay?" He chuckled.

"Yeah, was just bored out of my mind, so I came down here to join you." I shrugged, my eyes wandering between my crush and the tech in the lab as I casually ran my fingertips over the surfaces.

"Wow, thanks, I'm so honoured to be who you turn to when you're bored." Peter teased, making me smirk and bite my lip as I sat down next to him at the bench. I looked down at his suit, the wires exposed as he worked on it.

"What did you do to my dad's billion-dollar tech this time?" I returned the mocking as I looked at him. He smirked and shook his head, his gorgeous chocolate eyes flicking up to me briefly before looking back down at the suit.

"Got shot stopping a robbery. I was grazed at worst, suit took the brunt of it." He mumbled, his face slightly contorted in concentration as he continued to solder the wires.

"I'm glad, always better to have the tech shot than you." I smiled, making him return it as my eyes started to wander around the room again. My eyebrows furrowed as they fell upon a piece of tech that I hadn't seen before. And me noticing a new piece of tech was rare, given how often I was down here.

"What the fuck is this?" I mumbled as I stood up again, making Peter look up at me as I walked over to the mystery machine.

"No idea, all I know is that Bruce has been working on it for about a month now. But he hasn't told me what it does." Peter shrugged, the boy following suit to stand up and head over to it so that we were both looking down at it.

"Oh, look, a big red button." I smiled as I outstretched my hand and reached out to press it.

"What-are you crazy?" Peter scoffed, making me squeal in surprise as he grabbed my wrist at the last second and pulled my hand away from the button. I stared at him with wide eyes, my heart racing faster than I cared to admit at the contact that was currently happening between us.

"Pete, what the fuck?!" I exclaimed.

"When has it ever been a good idea to press a big red button?" He shook his head.

"Never, I know, and that's exactly why I'm going to do it." I smiled sarcastically, making Peter's eyes widen as I outstretched my other hand to press it instead.

"Y/N, no-." My skin collided with the button, both of us staring at it to see what it would do. Our eyebrows furrowed, Peter slowly letting go of my wrist as we both watched. My eyes widened, the anxiety starting to creep in as whirring sounds started to be heard from the machine.

"What the fuck is this thing?" Peter mumbled, making me gulp and shake my head as we both watched with wide eyes. My heart raced faster by the second, everything in me now regretting pressing that button as a light started to bloom from the window in the machine. It got brighter within seconds, making me gasp and squint harshly as within mere moments, the light became too overwhelming, and soon blinded me completely.

My eyes fluttered open, a groan leaving my lips as my head pounded harshly. I opened my eyes fully, the entire room spinning but slowly coming to a halt as I woke up.

"What the fuck?" I heard Peter groan as he came to as well. But my eyebrows furrowed. When he spoke, he sounded like...me. But that wasn't possible, I didn't see how it could be.

"Peter? Are you okay?" I asked, more confusion filling my head as whilst Peter had sounded like me, I had just sounded like...Peter. I forced myself to sit up, my head still spinning slightly as I sat up fully.

"Peter-." I looked back to my friend, but then everything stopped. My eyes widened, my mouth falling open and my heart almost stopping in my chest as instead of seeing Peter lying in front of me...I saw myself. What the fuck was going on? Peter groaned again, the eyes that were seemingly mine squeezing shut before opening again as he also started to sit up.

"What the fuck happened, did I pass out-." Peter looked at me, his face forming into the same shocked reaction as me as we looked at each other. Looked at each other with the wrong faces.

"Y/N, what the fuck, why are you in my body?!" Peter exclaimed. I gulped and shook my head as I looked down, more panic ensuing by the second as I saw Peter's body...but from his perspective. I was in his body, his beautiful, chiselled, yet completely terrifying body.

"Why the fuck are you in mine?!" I retorted as I looked back up at him. He gulped and shook his head, both of us clearly as panicked as the other as we looked at each other. But we looked at each other in the wrong bodies.

"What the fuck was that machine?" I scoffed as I scrambled to my feet and rushed back over to the device, but everything felt slightly off and clumsy considering that I wasn't myself. Literally.

"I have no fucking idea, but whatever it is, that button made us swap bodies." Peter nodded as he joined me in looking at the machine. I gulped and looked down at the boy, his body a few inches taller than mine.

"You do realise that we're going to be stuck like this for a week, right? The team won't get back for another six days." Peter gulped. My eyes widened, my mouth falling open as the realisation hit me like a truck.

"Oh, fuck-how are we going to do this? Handle being in each other's bodies?" I sighed as I held my hands up to Peter's gorgeous curls.

"We're just going to have to help each other out, I guess, and hope to god that Bruce has a way to reverse this. That's all that we can do right now until they get back." Peter nodded. I sighed and returned it, my mind already dreading having to live in Peter's body for a week. But we had no other choice, and so we had to make the most out of this incredibly crappy situation.

I sat on the sofa in the living room, my eyes reading one of my books as I just relaxed as much as I could whilst literally being in the same body.

"Y/N, help, help me!" I looked up, my eyes widening as Peter stumbled into the room, his arms desperately clutching his stomach as his eyes squeezed shut.

"Pete, fuck, what have you done, what's wrong?" I gulped as I shot up and rushed to him. After all, until the rest of the team got back, anything that happened to Peter happened to my body.

"I didn't do anything, it-it just started, it's excruciating, help." He groaned and shook his head as he continued to hold his torso. My eyebrows furrowed before I realised.

"Oh, Pete." I sighed, making him look at me as I rested my hand on his shoulder. When all of this had happened, two days ago now, I hadn't even considered the fact that I was due my period this week. Meaning that for this month, it would be Peter experiencing my period, not me.

"What's happening to me, Y/N?" He choked.

"You're getting your period. Or should I say, mine. Come on." I nodded, making his eyes widen as I took his hand and started to lead him to my room.

"W-wha-what do you mean I'm getting your period? I don't fucking want that." He scoffed and shook his head.

"And you think that I do? I'm sorry, Pete, but you can't do anything but ride it out. I've got plenty of products, I'll show you how to use them, and just drug yourself up on aspirin. You'll be fine, I promise." I reassured with a nod as I opened my wardrobe and got out my box of products.

"You're sure?" He gulped as he sat down on my bed.

"I love you, Pete, I do, but I go through this every month, every woman on the planet does. And if I can do it every month for years, you can handle six days total of it." I teased, making him sigh and give me a small chuckle as I started to get some pads out, and start to show him how to use them.

My eyes fluttered open, my lips parting into a yawn as I woke up to day number four of being in Peter's body.

"Fuck...me." I groaned and stretched out before relaxing back against the bed. But something felt...off. My eyebrows furrowed, the area around my crotch feeling heavier than it had done for the previous three days as I looked down at it. And then I realised why. My eyes widened, my mouth falling open and my heart skipping a beat as I saw the tent in my pyjama bottoms.

"Oh my...god." I scoffed, my Adam's apple bobbing in a gulp as I looked down at the clear arousal that I didn't dare touch. It was fair to say that this had not been how I'd wanted to see Peter's hard dick for the first time.

"Peter!" I yelled as loud as I could, every inch of me afraid to move in case something set it off. My door flew open within seconds, Peter looking at me with my own wide eyes as he looked at me.

"What, what's wrong?" He gulped and shook his head.

"What do I do, how do I get rid of it?" I returned his gulp as I looked down at the boner. Peter followed my gaze, his eyes widening further and a laugh leaving his lips as he saw what I was talking about.

"Oh, I'm so proud, your first boner." He teased and shook his head again as he walked into the room.

"Peter, this isn't funny, how do I get it to go down?!" I whined.

"Well, you either wait for it to go down, which may take a while...or..." He chuckled as he leant against my doorway and crossed his arms over my chest. I stared at him.

"Or what?!" I exclaimed.

"Or you...you know...help yourself, and that's how you get rid of it." He nodded. My eyes widened, my heart jumping violently in my chest at the thought of pleasuring myself...and Peter...at the same time.

"N-no, no way, I-um-no, I'm not doing that." I scoffed and shook my head. After all, everything would feel wrong about it. Not to mention that this was far from the way that I wanted Peter and I to hook up for the first time.

"Your choice, Y/N. Enjoy your blue balls, whilst I enjoy my period." He smiled, making me sigh as he turned and headed back out of my room.

Peter and I stood at the doors to the jetti-pad, both of us waiting anxiously as we saw the jetti get closer to the Tower by the second. We had just about made it through the week in each other's bodies, but now the team was literally minutes away, and so we were only stuck like this for a short moment longer.

"So, um...how do we tell Bruce...and your dad about this? Because I can already hear the angry lecture that I'll get from your dad at the fact that I've now seen you naked." He gulped. I returned it and looked at him, my heart fluttering violently at the fact that he was right. My crush had now seen me naked. Just not in the way that I had wanted that to happen.

"They're not going to believe us unless we tell them the truth. And then we hope to god that Bruce can reverse it." I nodded, making Peter sigh and return the nod as the jetti landed outside. The barrier lowered and the team walked out, making me gulp and give my dad a nervous smile as they walked towards us.

"Kids, hey! How was the week alone? I've missed my favourite daughter." Dad smiled as he outstretched his arms, making Peter's eyes widen as he walked straight for him.

"I've missed you too." I chuckled awkwardly as I put myself in between them. Dad looked at me with furrowed eyebrows.

"Um, thanks, Pete, but I was aiming for my daughter, not you." He nodded.

"Yep. Hence why I'm standing in front of you." I gulped. His eyebrows furrowed further, making me gulp again as his mouth fell open and his face dropped as he clearly realised what I meant.

"Oh my god-tell me that you didn't." He scoffed and shook his head as Bruce appeared next to him.

"Yes, tell me that you didn't." Bruce nodded.

"Once you tell us that this is reversible. Please." Peter gulped. Bruce scoffed and shook his head, dad clenching his jaw at us as they both stared daggers at us.

"You're damn lucky that it is reversible, aren't you? My god, come with me." Bruce shook his head again, making me breathe a sigh of relief and look at Peter as Bruce started to head to the lab, and we followed quickly behind.

My eyes fluttered open, a groan leaving my lips as my head pounded harshly. I opened my eyes fully, the entire room spinning but slowly coming to a halt as I woke up slowly but surely. But instead of having woken up on the floor of the lab like I'd done last time, I was instead in one of the beds in the medical suite. My eyes widened and I looked down.

"Oh, thank god." I sighed in relief, my eyes fluttering shut as they fell upon the sight of my own body laid out in front of me. I turned to look at Peter, more relief washing over me by the second as he too was lying in his bed, back in his own body. I bit my lip, everything about the boy perfect as he started to wake up as well. His eyebrows furrowed slightly, his lips parting as his eyes fluttered open. I watched contently, a chuckle leaving my lips as his eyes widened and he looked down at his body, just like I had done moments before.

"Oh my god, thank fuck." He gulped, making me smile at him as he turned his head to look at me.

"You're back too? We're back?" He asked with a smile.

"We're back. We're back in the comforts of our own bodies." I teased, making him chuckle and nod as we both started to sit up. I swung my legs over the side of my bed, though I stayed there as Peter stood up and headed to me so that he could sit next to me instead.

"So...what a bat-shit crazy experience that was, huh." He smiled, making me return it and look at him as he teasingly nudged my shoulder with his.

"Really was. I have to admit, though, it wasn't all that bad to be in your body for a week." I nodded.

"Wasn't too bad in your body, either. And, well...it made me realise something." He spoke softly as his eyes flicked over my face. My eyebrows furrowed at his words.

"Go on." I prompted. He gulped and looked at me, something about the look in his eyes telling me that he was scared about what he was about to tell me.

"I-I really like you. As more than just a friend, I have for a long time. And, I don't know, being in your body, experiencing life from your perspective, just made me want to tell you, you know? I-I get it if you don't feel the same, but I thought that you should know." He gulped, the boy looking as terrified as a deer in headlights as he looked at me. My eyes widened at his words, my heart jumping violently at his confession. At him saying that he felt exactly what I felt for him...for me.

"Pete, I...I don't know what to say, apart from that I feel the same. I've liked you for a long time too, I just didn't know if you felt the same." I chuckled and shook my head.

"Course I do. I'd be an idiot not to fall for such an amazing person." He smiled. I returned it and bit my lip, my heart racing so fast in my chest that I was afraid that it would burst out as I leant in and gently kissed him. Peter returned it, our eyes fluttering shut and his hand moving to hold my waist as I held his face. After a moment, I broke the kiss, unwavering smiles spreading onto our faces as we just looked at each other.

"Wow. Who would have known that accidentally swapping bodies for a week would turn out to be the best thing to happen to us?" He teased, making me laugh and shake my head as I leant in and kissed the sweet boy once more.