Chapter Text
Leo hates having heats. It lasts a week or so in mid to late spring, same for the rest of his brothers and has been that way once a year since they were thirteen. And for the past five times, he's detested the experience.
He can feel it approaching the days leading up to it, because he usually gets fidgety and restless. It makes meditating way harder, and all four of their performances tank during training.
What truly makes Leo despise having heats is the knowledge that there isn't anything he can do about it. Mating seasons are meant to motivate actual turtles to go and make more turtles. Except there is no “making more mutant turtles”, it's just him and his brothers, and none of them can even look each other in the eye during this plagued time of the year.
Jacking off in his room got old after the first few rounds, and waiting a day for his skin to stop feeling raw so he could jack off some more just made him squirm around and beg the universe to make it stop.
'I'm not making any more of me, and there's no one to do that with!' He yelled out in his head, envisioning himself scolding the void for being the idiot that it was. 'This literally has no purpose!'
It also doesn't help that of his brothers, he's the most… prude about sexual things. Raph and Mikey have a tendency to overshare, and they certainly have zero qualms about their heats. Is skin burn irritating? Yeah, but orgasms are the beeeest, man .
Donnie is more reclusive like him, but they can all smell each other's moods, so Leo unfortunately knows all too well that his blushing, unassuming nerd of a brother is one horny motherfucker.
Even Splinter has tried to have consoling talks with his eldest son in the past, about how the release of sexual energy is powerful and healthy for one's being. Leo just can't help but feel embarrassed about it all.
Which is, he supposes, one reason he finds himself standing on the fire escape in front of the most unabashed person he knows' window—Casey Jones.
The lights are shining bright through the grimy, haphazard window blinds. Leo can peek through the glass and in between the wonky slits of the blinds to see that the boy is definitely in his room, if the hazy outline of his figure moving around is any indication.
'What am I doing?'
Leo can't seem to get his trains of thought to stick around for very long through the thick fog of arousal in his mind. A nasty, hot gust of spring night, New York City air blows his mask tails towards the window, almost like a stupid, beckoning omen.
He sighs and taps his fingers against the pane. Suspicious brown eyes appear in between two blinds a moment later, widen a little when they realize who it is, then the blinds get roughly shoved up and the window cranked open to let the turtle into his room.
"You picked a good night for visitation hours, dude." Casey sings, going back to standing on his rumpled, unmade bed with miscellaneous things on it (sneakers, notebooks, his phone). Leo realizes he's tacking pictures to his wall, pictures of him with his sister, both of them with their dad, him and Red, the turtles, and a group photo they'd all taken with Splinter. "Dad's helping a friend move for the weekend, and Carson's at a sleepover."
Yes, those were indeed good things. Casey's dad and sister hadn't found out about the turtles (yet), so dropping by the Jones residence was pretty much only done if you were in emergency need of Casey.
Which he… might be.
Leo stood in a stiff stance by the wall opposite Casey's bed, in front of his desk piled high with schoolbooks and his PC. He clenched and unclenched his fists, fighting down the heat rising to his cheeks, as well as the shiver that kept zipping down his spine and shell every few moments.
Casey was just milling about in a pair of cotton, dark blue boxer briefs.
'Don't even think about it, Leo.' The ninja leader tore his eyes away from the round, musculare globes of his ass, clearly toned from skating around and playing hockey for hours on end. Also vigilante shenanigans. 'He doesn't even know heats are a thing… and he's a friend! No way.'
"What brings you to my humble chambers this fine evening, good sir?" Casey drawled in a damn near offensive approximation of some English accent. He turned to grin down at Leo while he said it, causing his obliques to flex from the twist.
Leo couldn't help the way his eyes darted down and back up the boy's body. 'He really doesn't care that he's almost naked while I'm here???'
He coughed lightly and flapped his arms a little, looking around the room. "Oh, I uh, was just passing through. On patrol. As usual."
Casey's boxer briefs were clearly well-worn, with the elastic from the waistband flying out in loose threads just asking to be pulled, and a small hole on the inside of the right leg. The boy pursed his lips in a comically exaggerated way. "... Without the guys?"
"... Yes…"
"What'd you fight about this time?" Casey deadpanned, turning to fully face Leo but remaining standing on his bed.
'Don't look at his dick don't look at his dick don't look at his dick don't look at his dick don't — '
"Oh, there was no fight." Leo admitted, glancing off through the open bedroom door. The wood floor in the hallway seemed fascinating to stare at. "My brothers and I just… needed some space for a little while."
He risked a peek back at Casey on the bed, who might as well have had steam pouring out of his ears, given how hard the gears in his head were turning.
"... I mean, seems natural enough…"
Leo picked up his unfinished thought. "But?"
"You look really sick, dude."
The turtle couldn't help the cocky grin that curled across his feverish face. "Thanks."
Said human looked unamused, and jumped down from his bed with a slight grunt to push some of his junk off, making it appear somewhat presentable. Then he shoved the ninja leader down to sit on his bed.
The mattress springs whined and covered up the very inhuman, very turtley squeak that left Leo when he came into contact with the sheets.
"You are not okay." Casey remarked with mild worry, suddenly very much in Leo's personal bubble. He went to touch the back of his hand to Leo's forehead, but the contact on his hypersensitive skin made him full-body shiver and gasp.
Casey recoiled, "Leo, what's going on, bro?"
The turtle chuckled breathily. "I… I need you to promise you won't judge."
Casey held up a hand while placing the other on his heart (although he was on the wrong side, but whatever, the sentiment was there).
Leo took a deep inhale. "You know… how we still have some… turtle… traits?"
"Like the white eye thing and the holding your breath thing?"
Casey, despite usually having the aroma of a gym locker room, smelled really, really good tonight. Like pine scented shampoo and that natural, tangy, sweet sort of musk that all humans (or at least April, Casey and Kirby) had.
"Eh… yes." Leo hesitated now, but the annoying, insistent flame swirling in his gut made him press forward. "Well, I—my brothers—"
He groaned and buried his face in his hands, letting the end of his admission come out muffled. "We're in heat."
There was a pause as Casey processed that information.
"... You're in heat?"
"Yes." His response was still muffled by his hands.
"... All of you?"
Leo nodded.
"... That explains why you've been off the grid for the past few days…"
Leo removed his hands but kept his eyes cast downward to the floor. "It's always this same time, every year, for about a week. And it sucks."
Casey had only met them for about half a year ago, so he didn’t know until now. April still didn’t know, actually. They’d simply told her they were grounded for a week when their heat came around last year, and she didn’t question a thing, still too new to undermine Splinter’s authority. This time, they'd just gone radio silent and had Splinter ready to reassure and turn April away if she showed up in the lair.
Casey eyed the blue banded turtle with inquisitive, slightly mischievous curiosity. "... Why'd you come here then, Leo?"
Leo meets his stare for half a second, then looks away again. "Because… I thought you could help?"
Casey spread his arms wide with a boasting smirk. "You, Leonardo, boy scout who never steps out of line, want to have sex with the infamous Casey Jones?"
"N-no!" Leo waved his hands in protest. "I—I just—"
He floundered for an excuse, but his mind went blank when Casey dropped to his knees and placed both hot, rough hands on emerald green thighs.
"Yes…"
Casey massaged his fingers lightly into the toned flesh, amused to find usually cooler, scaly skin to be much warmer. "Just helpin' a homie out."
Leo sighed and leaned back a little on his arms. “Th-thanks… um, you don’t mind if I…” He gestured awkwardly towards his crotch, causing the boy to bark out a laugh.
“Uh, yeah? What else am I ‘sposed to work with here? Whip the dick out, man!”
Leo bristled at his crude language, and found himself mildly shocked Casey wasn’t more uncomfortable or weirded out by this situation. “You’re not nervous?”
Casey’s hands paused. “Should I be? I know what I’m doing. I’m helping you get your rocks off so your heat… goes away?”
The turtle laughed breathlessly. “It won’t go away, but it’ll be way less strong, I think. But Casey…” He licked his lips, still a little hesitant to reveal himself. “I’m not, you know, human.”
The boy’s eyes flicked down to the bottom of his plastron, which still looked as normal as it always did, then back up to Leo. “I mean, you have a dick, right?”
“Yeah, but—”
“But it’s green?”
“... Among other things…” Leo trailed off, but Casey was growing exasperated. He roughly grabbed Leo and shoved him further onto the bed, crawling on top of him while Leo’s head hit the stripped pillow with a soft whap . Leo looked at his friend hovering above him with bewilderment.
Casey groaned. “Dude, just let em out already. The quicker the better.”
His heat got the best of him, so with a whispered, “Fine! Fine, just let me...”, Leo sat back up so he could take off his katanas, gear, and wrappings, just to be more comfortable.
Then, after laying down once more, he took a deep breath and slid the shell plate between his legs back into his carapace, and shivered at the air hitting his bare, wet slit. Casey, sitting back on his haunches between Leo's legs, took a gander, being incredibly curious as to what his mutant turtle friends’ genitals looked like. What, like you wouldn’t think about it?
He laughed a little in astonishment when he found… what kind of more resembled a hole than a penis. “What’s going on here, man? Walk me through this.”
Leo smirked and sat up on his elbows a little. “I thought you knew what you were doing.”
Casey didn’t respond, instead reaching out to run a finger down the slit, eliciting a shuddery gasp from the turtle. He raised his eyebrows and paused as the wet, sea green head of a penis began emerging from the folds. “... I’m kinda getting it. It’s a dick in a vagina!”
Leo frowned down at Casey. “No, it’s— uuuuh! ”
A hot, soft tongue just made an experimental lick against his cock head, and with that, the rest of his dick slid out into the open. A hand was quick to grasp him gently, and jesus christ he was sensitive during heats. Way more sensitive now that it was a strange, new, five-fingered hand touching him as opposed to his own.
“Pretty big, home slice.”
Leo was thankful for the dumb commentary because it reminded him not to take this whole, bizarre situation so seriously.
“I’m kind of turned on, actually.”
‘What.’
Leo sat back up with wide eyes and found that there was, indeed, a sizable tent in Casey’s dark blue boxer briefs. He met Casey’s laid back stare, and became even more flustered when the boy nonchalantly asked, “Wanna fuck me?”
“CASEY!” He yelped, scandalized.
“What? It’s between buds, and you’re horny as hell right now, yeah?” Casey got off the bed easily, wiped the fluid from Leo's dick against his briefs, then grabbed his waistband—Leo had to slap a hand over his eyes before he saw the human’s junk because man, did he need to get a hold of himself. He parted his two fingers when he felt the mattress dip, getting an eyeful of a pretty impressive, pretty pink cock surrounded by a trimmed border of black hair. His own green one twitched between his legs.
“Come on, I don’t have all night, and you’re not gonna last long.” Casey teased, sitting back on his knees and twirling an opened bottle of lube in his dexterous fingers, and a condom wrapper in the other hand.
"What's the condom for?" Leo questioned, pointing. "Neither of us can get pregnant, and I don't have STDs…"
"I don't either," Casey explained, already making moves to rip the wrapper with his teeth and roll the condom down Leo's dick. "But I'm not a huge fan of how cum feels inside me."
"Can't I just pull out?" Leo's voice was a little strained as Casey dribbled room temperature lube onto him and gave a few pulls with his hand.
"And leave me with that mess? Nah."
Leo protested. "But you're not putting one on—"
"My room, my rules, baby." Casey said with a cheeky wink, and Leo rolled his eyes. "Sheath the sword, yo."
Then the boy sat back once more, and was about to pour more lube on his fingers, when he paused and glanced up at Leo. "You wanna finger me, or let me do it?"
Leo remained silent, face bright red and his head absolutely swirling with how fast Casey was moving, and how comfortable he was in this circumstance. Donnie had only constructed their T-phones a year ago, and while Leo knew his other three brothers had already begun their foray into pornography, he still hadn't gotten around to it yet. So he had no idea how to finger someone open, boy or girl.
Casey made a face of realization as he pieced things together, "Waaaiiit, you've never done this before, right?"
Leo scoffed to try and offset how flustered and ill-equipped he felt. "Casey, I lived in the sewers for the first eighteen years of my life."
"Fair. Anyway," With that, Casey drenched his fingers in lube and reached behind himself—Leo had to stare up at the grimy ceiling fan with wide eyes and control his breathing. The squelching and sighing still rang in his ears, though. He balled his fists into the soft, cotton sheets underneath him.
After an agonizing few moments, the torturous noises stopped, and suddenly the world spun as Casey swapped their places, with his powerful thighs now strewn over emerald green ones and their cocks rubbing together.
Leo churred quietly at the contact, and the shit-eating grin Casey was throwing at him.
" That was an interesting noise." Casey hummed, cocking an eyebrow.
"It's—a turtle thing…" Leo panted sheepishly.
"A good noise?"
"Yeah…"
"Do all of you make them?"
"Yes."
"Does Don—"
" Casey ." Leo snapped, cutting the boy off. Not now, they both had needs .
The boy placed both hands behind his head, stretching his triceps and looking incredibly pleased with himself. He took a breath, and Leo watched in mild wonder as his ribs and chest muscles rose with the action. Casey smirked, "Have at it, cowboy."
Leo glanced between Casey's comfortable face and the nether regions now very close to his own. He gulped and took his hands from the sheets, placing them on Casey's muscular (hairy?) thighs and lifting his legs a little, granting him full view of the boy's ballsack (strange… his own were internal) and shiny, pink asshole.
The blue-banded ninja exhaled loudly. "Do I just…" He rubbed the head of his dick against the hole questioningly, unsure if anything he was doing was right.
"It's okay, take your time." Casey assured.
When you're in heat, there is no "taking your time". There's only more, more, more . So with a confident, very aroused huff, Leo began rocking his hips, pushing his dick bit by bit into Casey's tight, hot entrance. So hot, enveloping him, squeezing him, holy shell .
Leo breathed out a stuttery, high trill of clicks that made his jaw wobble, and Casey found he really liked how different and alien they sounded, while also being kind of… cute. He made a mental note to start trying to provoke those "turtle noises" out of the others more. Then he let out a pleasured groan as Leo bottomed out, the cool plastron hitting his cheeks with a muted plap .
"How you holdin' up there, dawg?" He called to Leo with a strained voice, who was groaning with his eyes screwed shut. "Lost in the sauce?"
"I can't—everything is so much more… more when you're in heat…" He explained through labored pants.
Casey heard that admission and decided to be a right little bastard by rhythmically clenching his walls around Leo's wonderful cock, while grinding his hips a little. He was rewarded by a gasp and a choked strain of churs tumbling from the boy scout's mouth.
Leo opened his eyes and growled a little, finally catching up. He gripped the convenient handles on Casey's body (hip bones, he'll later recall, when his mind is fully functioning) and began fucking the boy with animalistic frevor.
Casey let his eyes close and moaned gratefully, not bothering to be quiet or pretend that this wasn't exactly what he needed on a Friday night. His head tilted back on the pillow and bared his long expanse of throat, with his Adam's apple protruding as it did.
Clicks, groans, and grunts emanated from the creaking bed, with the headboard clacking against the wall with every thrust. As Casey predicted, Leo didn't last long.
Leo felt fire coarsing through his body with every second of his heat, and having actual, full-on sex for the first time in his life was turning him into a live wire. Casey was so tight around him, and it felt so good .
After one thrust, a choked yelp burst out of Casey, and he demanded, "Do that again."
Leo had no idea what he'd done differently. "Do what—"
"Aim up ." Was his command, and ever the obedient one, Leo did what he was told.
Apparently he struck gold, because Casey made that noise again and bucked back, fists gripping his pillow with white knuckles.
Leo made a shaky mental note to ask what he'd hit later.
His orgasm built quickly in his gut, pressure rising and rising. Finally, he came with a shouted burst of loud, clear clicks, making his throat and the very walls vibrate.
Leo quaked and whimpered where he was, still buried inside Casey but slowing to a stop. Casey, with loose, black hairs sticking to his forehead, cackled softly and took himself in hand, working himself the rest of the way to orgasm with a couple tight, fast humps. He also came with a yell, though his was raspy and guttural, letting his seed splatter all over his abs and torso.
Finally, Leo pulled out, and they both wilted with tired sighs, labored breathing, and softening cocks.
After a moment to regain his higher thinking, Leo squinted down at his dick and and the… ahem… filled condom around it. He shuffled awkwardly over to Casey's trash can by the door and gestured to it with an unspoken question. Casey give him a simple thumbs up from the bed, flopping down and still panting while Leo peeled off the condom with a grimace, tied it off, trashed it, and retracted his cock. He meandered back to sit on the edge of the bed, where Casey was already dabbing at himself with tissues.
"So, just to be clear, no weird feelings between us?" Leo questioned hesitantly, hopefully.
Casey looked up and grinned. "Course, man. 'Sides, I got eyes for Red and Red only."
Leo smiled and rolled his eyes, silently not believing either Casey or his brother had a shot at winning April's heart, at least not while they kept their infuriating rivalry up. "Let me know how that goes for you."
It was weird, for sure, that Casey could have sex with a friend while still exclusively having romantic interest for someone else. There was a lot he had to learn, evidently.
"I'll see you guys… when?" Casey asked, getting up to throw the tissues out and pull the same pair of dark blue underwear back on.
"Give us maybe another week." Leo answered sheepishly, then remembered something. "Hey… could I use your shower while I'm here?"
Casey regarded him with a questioning look.
He elaborated, "If I go back—they'll be able to smell you on me…"
Casey's eyebrows promptly left the planet, and he guffawed. "Another turtle thing?"
Leo grinned and rubbed the back of his neck. "Yeah."
" Well ," Casey spread his arms, turning around where he stood in his room. "The shower's yours. Have fun."
"Thanks." Leo smiled and headed down the hall, towards the bathroom.
Heats sucked, that was for sure, but he was doing pretty alright this time around.