"Are you sure about this?" Leo asks as he follows Karai into the bedroom.
"Relax, Leo," Karai chides as she locks the door behind them. "Raph's fine."
"Then why does he look like he wants to kill us?"
His brother grunts from where a very sturdy-looking chair beside the bed, bound in place with an elaborate tangle of red ribbon and strong-looking rope, complete with a bow on top of his head and his own mask stuffed in his mouth. Green eyes blaze in a way Leo rarely sees outside of the battlefield, or when Mikey's grabbed the last pop tart.
"'Cause he's being a big ol' grumpy-wumpkins," Karai teases, walking to squish Raph's cheeks. "Isn't that right, you big ol' grumpy-wumpkins, you?" Raph growls--and okay, Leo has to admit that it's one of his sexier growls, but. Still.
Karai sees the indecision on his face and rolls her eyes. "Leo, it's okay. This was his idea, remember?"
"Only because we got into the eggnog early and he put it on that Post-It note taped to his forehead!"
"Fiiiine," Karai turns to Raph, hands on her hips. "Can you safeword for the worrywart here, grumpy?"
Raph huffs, but obediently snaps his fingers twice.
"See?" Karai turns back to Leo triumphantly. "He wants to play as bad as I do." She traces a hand down Leo's chest, her words suddenly half-mocking and half-serious. "Do you want to play with us?"
And well....Leo looks at the shimmer in Karai's eyes, lets himself admire how very pretty Raph looks as he quivers and flexes. What can he say? Leo's a red-blooded turtle, in the end. He nods.
Karai grins devilishly and pulls him into a wet, filthy kiss, her tongue wiggling down his throat as she reaches to grab his ass. It’s nothing they haven’t done before, but Leo’s suddenly keenly aware of Raph’s eyes burning into them and he’s blushing by the time Karai pulls away.
She giggles at the sight. “Isn’t he pretty?” she asks Raph, reaching up to rub a gentle thumb along Leo’s rose-red cheek. He leans into her touch almost automatically and Raph lets out a muffled complaint, twisting in his restraints until they start to crinkle.
Karai ignores him. “Why don’t you strip for us, baby?” she says, kicking off her shoes and flopping onto the bed. Leo reaches up to undo his straps, movements that he’s practiced more times than he can count suddenly stiff and awkward at the idea of an audience.
She lets out little coos of appreciation as he works, talking about how handsome and muscled he is, how he has such a darling blush, how he’s such an obedient little turtle. He tries to tell himself she’s just saying these things for Raph’s benefit, but they make his stomach grow warm and tight nonetheless.
When he’s fully undressed Leo crosses his arms over his chest, feeling ridiculously exposed considering how little he’s actually taken off. Karai laughs at the sight. “Aw, poor shy darling.”
She pats the bed beside her and Leo settles onto the mattress, keenly aware of the fact that she’s still fully dressed. Karai pulls him into another kiss, forked tongue flowing out of her mouth so it can lap along his jaw and paint his lips with shining spit.
She gently turns Leo’s head, focusing him to face his brother’s big, hungry eyes. Raph has gone crimson by now, flexing his hands like he wants to punch to something.
“Don’t look away,” Karai whispers in his ear. “Let him see what you are. Show him what I can do to you.” She moves behind Leo, planting one kiss, then another, along the curve of his neck. His breath hitches and his hands fist on his thighs.
More kisses along his shoulders, and her snakes are getting in on it, fingers melting together into tongues flicking down his sensitive sides. Leo squirms at the sensation, feeling blush creep down his neck. Raph’s eyes are boring into him like goddamn gun sights.
“Oh, he likes this,” Karai whispers. “Can’t you smell it?” Leo’s not sure who she’s talking about, but she’s absolutely right. The air is a thick haze of arousal–Leo’s, Raph, Karai’s. Their combined scents are more than enough to get him hard, and he can see a similar bulge between Raph’s legs.
Karai drags a snake-mouth across his plastron, with just a hint of fang, and Leo gasps. She chuckles. “Look at you go. Baby brother could never make you feel half as good, could he? Not even if he used that stubby little cock of his.”
Leo doesn’t know whether it’s the baby brother or the suggestions about his size, but Raph lets out a roar, ropes creaking as he frantically thrashes like a hooked worm. And fuck, but it’s hot to see Raph like this.
He’s close enough to touch, if Leo wanted to, to touch and let himself be touched, but he doesn’t move from his place on the bed. He just looks at his brother’s rage and it doesn’t irritate him, or quietly frighten him, the way it usually does.
Instead it makes his heart flutter almost as badly as the kisses buzzing over his skin, as the curve of Karai’s breasts nudging against his shell. He feels wanted–needed–in a way that’s so wrong and so intoxicating.
So when Karai purrs “Drop,” in his ear, Leo does without breaking eye contact with Raph. He’s still blushing worse than ever, of course, but that doesn’t stop him spilling into Karai’s (thankfully human again) hand.
She sweeps him up with a proud little giggle, running her thumb along the curve of his head in that slow, steady way that drives him while. Leo churrs desperately, and Raph churrs back, because–fuck, he’s out now, cock rubbing desperately against the unyielding surface of the chair.
“Such putting, greedy cocks, both of you,” Karai says conversationally, still toying with Leo’s cock in one hand while the other–still a snake–laps and sucks at his neck. “I ought to keep you both in little cages, put you on display all time, make you beg for me to play with you.”
Raph’s eyes go wide at the possibility, but all Leo can think about it is how hot the mental image is. It’s almost enough to make him cum right there, but Karai abruptly pulls away, cackling at his distressed whine.
He twists around on the bed to find her casually sprawled on her elbows, legs spread–is she damp? He’s pretty sure she’s damp, and a quick sniff confirms it.
“Take off my clothes,” she orders. He bows his head and reaches out, but Karai slaps his hand away. “Nu-uh, Blue. Put that pretty little mouth of yours to work instead.”
The self-consciousness hits him all over again as Leo carefully bends to snag his teeth in her waistband. Raph’s still letting out desperate little churrs as Leo drags the pants down Karai’s legs, carefully not to graze her skin with his teeth.
The socks are a little unpleasant, but not too foul–certainly a lot better than Casey’s, and he gets to lick her toes at the end. He forces himself to save the underwear for last, instead moving up to gather the hem of her shirt in his teeth.
Karai obediently lifts her arms over her head, letting Leo grab the shirt up off her torso and fling it off the bed. It accidentally (or not so accidentally) flops onto Raph’s thigh and his brother hisses, almost knocking himself over in his attempts to shake it off. 
Her bra is tricky. Leo wastes a stupid amount of time listening to Karai giggle as he fumbles with the catch, before deciding fuck it and grabbing it off his teeth. Her hair is sticking in every direction and her face is flushed by the time he finally drags it off, and she’s laughing, the kind of rare, open laugh that Leo wants to collect in a bottle.
Finally, the underwear. Leo makes his way back between Karai’s legs, brushing her face over the soft hairs on her stomach. Her panties are black, with soft white frills, and they’re so rich with her unique, perfect scent Leo has a fantasy of ripping it to pieces and swallowing them down.
He settles for carefully dragging the panties down Karai’s legs, inching farther and farther down until his own legs are almost falling off the bed. Her dark, shining hair moves over his face and he’s churring him, lightheaded with the sheer obscenity of it all.
When he finally sits up, the panties hanging from his mouth like a dog, he’s half out of his mind with her smell. Karai kneels before her and gently tugs the panties out of his mouth, smearing her fluids over her haze until he’s dizzy.
“Look at that,” she whispers, setting the underwear aside and pulling him into another kiss. “Look how pretty you are, Blue, marked up with me.” She pulls him to face Raph. “What do you think, grumpy-wumpy?”
And Raph….fuck, Raph’s eyes are white by now. His face is an unholy mess of all-consuming lust and white-hot rage, and there’s drool flowing from underneath the gag. His leaking cock is trembling as he ruts against the chair sheet.
“You want him, don’t you?” Karai says, resting her chin on Leo’s shoulder. He wants to turn and look at her, but he’s physically unable to stop staring at his brother.
“Want to pin him down,” Karai muses. “Yank his legs apart, fuck him raw and hard until all he can do is scream your name. You’d fight armies, burn cities, cut out your own fucking eye just for the privilege of laying a finger on him. Isn’t that right?”
Raph nods desperately. Leo has never seen him beg for anything before, but he knows this is what it has to be.
“Tough,” Karai says sweetly. “Leo, darling, why don’t you get on your hands and knees and show him what that clever tongue can do?”
Leo draws in a rattling breath, so turned on it hurts. He can distinctly hear his brother panting behind his gag and if he’s being honest, he wants to put that sound in a bottle, too.
He goes back between her legs, but this time there’s no barrier of cloth between him and her cunt. It’s not the first time he’s tasted it, not by a long shot, but it never feels anything less than what humans call the divine.
“Fuck,” Karai groans as he flicks her tongue along her clit, digging her fingers into his shoulders. He picks up the pace, emboldened by the sounds she’s making, unable to avoid the little rush of power that comes with leaving her breathless with pleasure instead.
At least until her arms extend again, two snakes rippling down his shell. One of them flips his tail up, and Leo barely has time to let in a shocked breath before a warm, wet tongue slips instead his hole.
“Naah!” He almost gags on Karai’s cunt and she lets out a sharp gasp of pleasure, while Raph makes a strangled sound. 
“That’ssssss it, baby,” Karai rasps, her words melting into a soft hiss. “Let me fill all your greedy holes.” She grinds up against his face, pushing back against the tongue up his ass, and Leo’s vision flickers. Raph lets out something that sounds a bit like a screech.
Leo forces himself to pull together, to keep his mouth busy with Karai’s cunt. It’s a tough task with first one, then two tongues thrusting inside him, pushing and rubbing at his inner walls. Occasionally one of them will tease his prostate, leaving him trembling and damp with precome.
The background soundtrack doesn't help him concentrate, either. “You’re ssssso cute when y-you’re jealousssss, baby,” Karai breathes, her voice hard to hear over Raph’s incoherent yells.
“Hissss little hole, oh, you don’t know how tight it isssss.” She thrusts her hips as her thighs begin to shudder. “Our Blue, he n-needsssss to be kept nice and full. Pity you didn’t make the c-cut.”
And then she’s coming, filling Leo’s mouth with the kind of perfect taste for which there are no proper words. The snakes hiss with triumph where they’re still buried inside him, and Leo churrs frantically at the vibrations.
Karai slumps forward with a groan as the last few waves die away, tilting her chin to make him look up at her. “Tell me, Blue,” she whispers. “Do I taste better than our grumpy old man here?”
Leo stares up at her blankly, too lost in pleasure to even consider answering the question, and Karai laughs. “That’s okay. I think we all know the answer, don’t we?” She delivers this last to Raph, who responds with an almost pitiful groan.
The tongues start sliding out and Leo lets out a panicked little whimper, hips wriggling. “Hush,” Karai says firmly, her hands turning human so she can give him a comforting pat on the shoulder. “It’s okay. I just want Raphie to see your pretty little hole.”
She maneuvers Leo until he’s got his ass facing his brother, his slick, flaming face pressed into the blankets. Karai tilts his hips high enough for Raph to also get a look at Leo’s cock, heaving and drenched between his legs.
“Hold your cheeks apart for us,” Karai orders. Leo’s hands move almost of their own free will, opening him up enough to expose his hole to cool air. He hears Raph making a gagging sound.
“Look at him,” Karai says. “So stretched and pink and perfect. With a little more work he could be ready for my fist, how about that?” Leo groans, and Raph’s breath hitches.
He turns to look at his brother, shocked to see how deep the rope has dug into Raph’s skin. It’s going to leave bruises for sure. Raph’s eyes are wild, flickering white and green, his cock dripping. He looks like a touch might be enough to make him come.
“Desperate. Needy,” Karai says thoughtfully, and Leo can feel her hand caressing his ass. “But not as desperate as you, right, Raphie?” She has a point; Raph looks pretty fucking desperate.
Karai slides off the bed, and Leo feels a wicked bit of satisfaction at the slight wobble in her legs as she makes her way over to Raph. She runs a finger along his neck, under his chin, scratching her nails over the curve of her jaw. Leo watches as she slowly, painstakingly peels off the tape, chuckling when Raph lets out a little whimper.
“Do you want to fuck your brother, Raphie?”
“Yes,” Raph sounds like he’s been choking on gravel. It somehow turns Leo on even more than he already is.
“What about you, Leo?” Karai nods over at him, giving Leo permission to sit up and look at them properly. “What do you think?”
“Hmm,” Leo cocks his head, pretending to mull it over like he isn’t very aware of how nice and swollen Raph’s cock is right now. “Well, it wouldn’t be in the holiday spirit to leave the poor thing like this, is it?”
“I suppose so,” Karai muses. “Then again, he’s been such a naughty little turtle. Being so cranky and putting a damper on everyone’s fun.” She shakes her head sorrowfully.
“Suck my dick, you–”
“Ah, ah,” Karai warns, holding up the gag. “Do you want me to go get the strap-on and ruin our boy for another hour or two?”
“No!” Raph’s eyes go wild with real panic. “No, no, I–” He jerks to a halt, chest heaving.
“Yes?” Karai asks.
Raph sucks in a breath, glancing around the room as if there’s something here to save him. “I–I–fuck.”
“Come on, Raph,” Leo teases, a hint of impatience coloring his voice. “We don’t have all day.” He spreads his legs just a bit wider, nibbling his lip. “Unless you want to see if Karai’s bigger than you in all the right places–”
“Fuck!” Raph yells, throwing his head back. “Let me out of this thing, pretty fucking please?”
“Good enough,” Karai says, and then she’s pulling Raph into a knife as she plucks a knife from the folds of the shirt on his leg. She cuts a single rope with a sharp snap, and that’s all Raph needs before exploding out of his restraints with an unholy roar.
He grabs Karai and throws them both on the bed, bodies crashing down on Leo in a tangle of limbs and hot, pulsing arousal. They end up with Leo on his back, Karai sinking onto his cock with her shoulders braced against Raph, who’s finally able to push into Leo’s hole with an exultant churr.
They shudder together on the bed, clawing at each other’s bodies, Raph and Leo both rubbing at Karai’s clit until she shudders around Leo’s dick in a second orgasm. Leo comes not long after, and then it’s Raph, filling him up what feels like over a minute straight.
Their throats are all sore from screaming before it finally comes to an end, folding together in a living nest of warm, sticky bodies. Leo’s head is spinning, he feels like he’s going to be smelling his siblings’ fuck-smells mixed in with the Christmas cookies for a week, and he thinks he can hear wrapping paper crinkling somewhere. It’s wonderful.
“Assholes,” Raph sighs happily, pulling Leo into a sloppy kiss. “You two are fucking sadists. I can’t believe they call me the crazy one.”
“You still have a bow on your head,” Karai points out.
“Fuck you,” Raph mutters, face-planting in the pillow. “It adds to my roguish charm.”
“You have a roguish charm?” Leo asks.
“Fuck. You.” Raph groans.
Karai sighs, arms stretching enough to wrap around Leo and Raph both while her snakes plant little kisses on their heads. Leo kisses one on the nose, and Karai giggles.
Leo lets himself lie there, bathing in their warmth. Leo feels safer and more loved than he thought possible, and if there’s anything from tonight he would bottle if he could, it’s this.