TMNT Oneshot

RiseLeo x GNReader: Sin, Cos, Tan

Request: Alrighty so firstly I love your writing it is absolutely *mwah* chefs kiss augh I love it. The way you write the characters is perfect! Secondly, I came up with this idea when I had to do summer school and was struggling a bit with it. Could you do a Rise Leo x reader where the reader has studying sessions with Donnie where he tutors them and Leo gets jealous and tries to help even though he doesn't have a clue about math or science or anything like that? Lastly, if you can't get to it I totally get that. Make sure to take care of yourself and drink plenty of water!

A/N: Howdy! I hope this fulfils your idea, I'm not sure if I did your vision justice entirely, but I sure as hell tried. Enjoy!

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Leo could hear their voices from down the hall, quiet laughs seeming boisterous as it echoed against the high ceilings. He had to inspect it, but he knew deep down what it was already, pushing the ugly green head of jealousy further down his throat as he approached Donnie's lab.

And there you were like you said you'd be, sat beside his genius brother with a few books out in front of you and a warm smile on your face. Your pen bumped against the curve of your lips as you whispered to Donnie your proposed answer, as to not disturb the peaceful silence that surrounded you both. Leo's eyes couldn't help but focus on your form, how you sat so elegantly but still appeared so invested in whatever Donnie was spouting out.

"What was that dumb rap you did again?" he heard you question, soon followed by a loud gasp coming from the soft-shell turtle. Faining offence, Donnie's right hand flew to his chest, brows raised in mock frustration, "How dare you! You're just jealous of my lyrical skills."

"You still didn't answer my question," you butted in, turning away from your work with a sickening smile. Leo felt his knees wobble at the sight, knowing that you usually shared that look with each other before causing some mischief. He couldn't help but think you were replacing him with his brother, choosing to spend your weekend with Don instead of with him.

"Okay, so it goes: Loom 16, take corridor B, down the stairs past the Ibis Tapestry-"

"Loom? You mean room?"

"What? No! Loom, let me find a dictionary-"

It's not like you were obligated to spend all your free time with him, but it was nice when you did. He never laughed so hard when he wasn't with you, would have never created such horrid drink concoctions then trick Raph into drinking them. Maybe he was jealous?

"What? No- no, I can't be jealous. What am I jealous of? Homework, pfft, for once I've got to stop thinking." Leo muttered to himself, his grip on the doorway tightening as the thoughts crept in. At the sound of his muted words, your attention turned to the red-eared slider that stood idly by the door. You quirked a brow at him, suddenly confused by his appearance, "Leo?" you questioned. At the mention of his name, Donnie focused on his brother, slightly peeved that he had been eavesdropping on them both.

Leo jumped back into reality, strolling into the lab as though he wasn't just stood there gawking at you for an unrecorded amount of time. He fingered the pages of the book you were meant to be looking at, scanning the number of equations that he didn't really understand.

"Leonard, what are you doing here?" Donnie sighed out, growing irritated with the intrusion. Leo straightened his back, glaring at Donnie, "What're you doing here?" he huffed back in retaliation. Donnie had never wanted to slap his brother more in his whole life, "I live here." was his simple response, followed by his brows dipping further down his forehead.

Leo's eyes widened, god, he looked like such an idiot right now. Acting as though that didn't just happen, Leo went back to the maths homework forgotten by his intrusion, "So what do we have here?"

"Well, before you so blatantly interrupted us, I was helping (Y/N) with their maths homework." Donnie stated, the pencil in his hand splintering as his brother continued to plague him. Leo nodded along, "I can help if ya want?" he asked, looking away from his brother to gaze at you, he only ever cared about your response.

You looked between the two, feeling conflicted: on one hand, you really enjoyed hanging out with Leo, of course, the little crush you had on him definitely didn't help. But on the other hand, you knew Donnie would actually be able to help you with your homework and wouldn't goof off and distract you.

"Lee, you're welcome to stay and help us, but I do really need to get this stuff finished before we can hang; is that okay with you?"

How could it not be okay with him, especially when you asked him like that! Pulling a chair from the other side of the room, he took his time to prolong the screeching sounds the ends made across the lab floor; just to pester Donnie.

"Of course I'll stay, I can even help!" Leo cheered, relishing in your beaming smile knowing he had caused that. Donnie suddenly bopped back into the conversation, finally understanding why his loser of a brother was acting the way he was. Deciding to have fun with this, he let his thoughts go, "And how do you plan on helping (Y/N) with their advanced mathematical equations?"

"I-er, well-" Leo stuttered out, unsure how to keep so suave under this amount of pressure Donnie was putting on him, he must have been able to work out his motives quite quickly. Donnie's devilish smirk struck a nerve in Leonardo's body, hands forming into fists, "I can be moral support, no doubt whatever you're saying is boring as shell." he hummed out, feeling his cocky nature return like an old friend.

Donnie huffed, folding his arms over his plastron as he got back to work teaching you. He could sense Leo's glare burning through the goggles that resided on his held, practically feeling the hot metal trail down the sides of his face.

After numerous attempts at the same question, and failing every time, you gave up. You slumped back into your chair, a whine falling from your lips, "I can't do this, the questions so dumb! It's basically impossible!"

"It's not impossible, you're just not getting it. If we keep trying with this method you should be able to crack it."

"But Donnie, I don't understand this method, that's the problem!"

"Well that's not my fault, I've taught it to you in the most basic way, there isn't any other way to explain it!"

The argument between you two was becoming heated, voices rattling so loud it awoke Leo from his nap that he had so graciously taken while you both worked away. Kicking his feet up from the desk, Leo watched as you two yelled at each other red in the face, "Woah, woah, what happened?" though he's pretty sure he heard it all anyway.

"Donnie isn't explaining this method to me in a way that I understand!"

"Oh yeah, well- well (Y/N) isn't doing a good enough job at understanding the method!"

They both roared, sending Leo slightly deaf. Standing up, he made sure to place a bookmark on the page you were on before closing the book, you and Donnie cursing him for such a thing. You moved to go open the maths book again but your hand was slapped away by Leo's, the slap wasn't harsh and his eyes told you he knew what he was doing.

"It sounds like to me, you're both pretty stressed and have been sat here for hours now! Looks like you need to relax, maybe spend some time with good ol' neon Leon, hm?" he aimed the last part primarily at you, wiggling his non-existent brows. You let out a small giggle, smiling at him with a twinkle in your eye. Donnie pretended to throw up in his mouth, pouting as he spoke, "Pass."

Leonardo waltzed around the desk, standing in front of you with his arm stretched outwards, you took it into your own feeling him pull you up onto your feet. He refused to let go of your hand, keeping it looped in his as he walked you out of the lab and to the kitchen to get some food since he knew you hadn't eaten all day.

Donnie slumped against the chair, glaring at the maths books with vengeance. Pushing them to the floor with sweeping hands, he pulled out some random invention he was working on and hummed to himself as he worked.

"Donatello, with a book in his hand, saves the day and proves to everyone that he's the man."