Archive of Our Own ^beta

Leo had been awake for days at this point, his vision starting to blur at the corners, yet he still couldn’t get his mind to shut off like he wanted it to. His brothers noticed, they always did, but they were unable to offer any help to the exhausted slider, not for lack of trying, mind you, but because Leo wouldn’t allow it.
Raph had tried wrapping Leo up like a burrito, attempting to rock the leader to sleep like he used to when they were tots, only for an hour, or more to pass with nothing happening. In truth, Leo was biting his tongue, or digging his claws into his palm the whole time to keep from sleep.
Leo ate around, or refused to consume the food Mikey would make him, whenever the youngest tried to slip sleeping pills into it. Leo could tell when he did this, by the way his smile got too big, his eyes darted all around the room as he talked. It was a tell that Leo had noticed back when they were tots.
April and Splinter would try sneaking sleep aids into his drinks, a taste which Leo had picked up on when he was ten and managed to avoid.
The only one who could get him, was Donnie, with that fucking tranq bo of his.
And that was what had led to this moment, with Leo currently ninjaing his way down the halls, on his way to the bathroom. He’d been portalling around all day, trying to keep himself away from his twin, while fighting bad guys. He couldn’t risk taking any “Friendly Fire” in the way of his twin “Accidently Missing” his shot or “Pushing the Wrong Button” because his “Finger Slipped.”
Needless to say, Leo didn’t buy the soft shell’s excuses. The rest of his day had been locked in his room, pretending to sleep by ignoring the soft knocks and call of his siblings. It was enough to fool the other two, but not Donnie, who had cameras all over Leo’s room.
So, the slider had waited until three in the morning, when he was certain that his beloved twin was dead asleep, before finally slinking out. He had to piss so bad and it was this urgent need, along with his belief that Donnie wouldn’t risk Leo making a mess which he had to clean, that made the slider sloppy.
Leo never saw it coming, when he opened the bathroom door. The only indication that something was wrong was the soft shick sound of Donnie’s Tech Bo, as the mechanics turned and shot the dart at him and the pain in his shoulder, where the tranquilizer embedded itself in his flesh.
“Fuck.”

Donnie’s nose scrunched in disgust, as he watched Leo’s body crumble, his bladder giving out and covering the slider in urine.
He should have expected this outcome, but whatever. Donnie could deal with it.
Tapping on his Tech Gauntlet, Donnie called his drones to clean up the mess on the floor, before he began to strip himself of his gear, handing it to the first drone that arrived, while another turned on the tap to run a warm bath.
The metal arms of Donnie’s Spider Shell picked up Leo’s limp form, stripped him of his gear, and wiped most of the mess from the leader's body with a warm wash cloth.
Satisfied that the worst of the damage was cleaned up, Donnie had the extinction arms bring his twin over, where he picked up the elder turtle, before dismissing his Spider Shell.
The water was the perfect temperature, when Donnie stepped in with Leo. Hot enough to prickle the scales and clear the sinus’, without truly burning them up. It was only Leo and Donnie who liked their baths this hot, which had caused some fuss for Splinter. Donnie remembered that their father had told them that the water was so hot, they might just turn into turtle soup. They hadn’t understood what he meant back then and had even gotten in the habit of saying ‘want tot soup’ anytime they wanted to bathe. Eventually they had grown out of that habit, but it was a fond memory. One that Donnie held close to his heart. What had never changed, was the twins taking baths together, even after they were old enough to know better. No one said anything, even if it bothered them, not that it mattered to Donnie either way.
Leo was the most important thing in Donnie’s world, even more so than uranium and that was saying something, so it was no wonder that the soft shell took every opportunity to be this close to his other half.
If truth were to be told, the soft shell wanted to be even closer to his twin, more intimate. He knew it would never happen, Leo only saw the genius as his dorky brother, but…Donnie would take what he could get in little moments like now, when he could freely hold his beloved twin the way he wanted to.
It’s why he had the most cameras in Leo’s room, why he was always at the slider's side, why he loved when Leo stayed up for days at a time.
To clarify, he hated that the leader was hurting himself by not sleeping. The part he loved was when Leo finally went down.
Mostly because he was the one who usually tranqued the slider and Donnie always made sure it was extra strong. He’d worked extra hard on the serum, making certain the dose was as high as he could get, without it being lethal.
He needed Leo to be dead asleep, with no chance of waking up.
Because of times like this, where Donnie could be all alone, in private with his beloved.

A soft moan escaped Leo’s lips, the sound drawing the soft shell from his thoughts and back to the present, where he focused his attention on the still sleeping leader. His hands had begun to roam his brother’s body, while he was lost in his thoughts, pausing on Leo’s lower plasteron for just a moment, before slipping even lower.
The tub was an old hot tub that had been salvaged with Raph’s help and repurposed to fit them all. Meaning, it had plenty of room for Donnie to be able to open Leo’s legs wide, draping one on either side of the genius’ knees with room to spare.
Grinning, Donnie shifted them both to face one of the many spy cameras that he’d installed around the bathroom head on. He knew it would record and he would be adding this session to the massive collection he had with all the other times he’d done this with Leo.
Donatello Hamato was a turtle of habit, everything he did had to be according to plan. If anything changed, he got nervous. Which was why he never confessed his true feelings to his twin. Fear of rejection and change was a bitch, yet it was also a comfort in moments like this.
Because he would never risk his twin hating him, but could still have his twin's body, just the way he wanted.
As always, Donnie began his session by reaching down to part the delicate lips of his brother’s cloaca, having learned over the years how to keep his fingers out of the way of the camera angle, so he could see everything later on.
Then his finger slipped deep inside Leo’s soft, tight channel, angling just right to touch the slider’s sweet spot, stretching his twin out to his limits with only a single digit. Another soft moan was pulled from the slider's throat, his breath starting to come in soft pants as his arousal began to burn low in his belly.
Donnie knew his twin was feeling good from the copious amounts of slick which began to coat his finger, as he thrust it in and out of his brother slow and gentle.
Leo’s cloaca rippled against the soft shell's scaled skin, as he worked in a second finger, forcing the sleeping turtle to stretch even further.
Using his free hand, Donnie turned Leo’s head to the side, capturing his lips and swallowing the unfiltered cry of pained pleasure, which slipped from the shorter turtle's lips as it fell.
A moan of his own came from the genius’ throat, followed by several turtle like clicks, which seemed to excite Leo even further in his sleep.
Perfect, just the way Donnie liked it.
Several moments passed, as the younger twin worked his brother open more and more.
As the years had passed, Leonardo had gone from being the taller twin, to the shorter one. Meanwhile, Donatello had shot up like a tree, becoming larger in all aspects, than his beloved slider. This was why the soft shell took his time in opening the leader’s body.
Once Donnie was certain he’d prepared Leo enough, he gently eased his fingers out of his mate, then shifted them, until he was able to slide his cock deep inside the other's body.
The soft shell wasn’t religious, he had no clue what lay on the other side of death for any of them, but he was certain that no paradise could come close to the sheer glory that he was feeling now. Leo’s cloaca was heaven and it took everything within the genius to keep his turtle and Yokai instincts at bay. He NEEDED to bite, to mark his twin as his mate. So everyone would know who Leo belonged to.
He couldn’t.
Because then everyone would know and that would change everything. Their father would throw them out, their brothers would shun them, their friends would turn their backs on them…That was if Leo even chose his twin, over their family, if Donnie’s sick desires were to come out.
He couldn’t risk it.
So, instead the genius simply gritted his teeth as he wrapped one arm around Leo’s plasteron, holding him by the shoulder, his other hand gripping his thigh, while he guided the leader's body up and down.
The soft sound of water sloshing against the side of the tub intermingled itself with Donnie’s harsh pants and Leo’s gentle mewls of pleasure. Curses came from the soft shell as he picked up his pace, slamming near violently into his twins body, his movements coming more erratic by the second while Donnie worked himself towards orgasm.
He could feel Leo’s cock, trapped within the protective sheath inside the slider’s body by the genius’ own wide member, pulsing with pleasure against his own. It was a clear sign that his twin, his mate, was right on the edge with him.
Donnie could feel it in his very bones, through that twin sense they claimed to have.
The soft shell pulled his beloved flush against him, his cock buried to the hilt inside the leader's tight, wet heat. Deep inside Leo’s body, the flowered head wrapped tight around the opening to the slider’s womb, creating a seal. The tiny tendrils at the head's center, forced their way past that opening, right into the elder turtle’s womb, seconds before Donnie came, filling his mate's womb.
Absently, Donnie felt his partner's cock pulse against his own, still trapped within its sheath, held back by the soft shell’s own as Leo also came inside himself. The soft moan of completion which escaped the leader’s throat was music to Donnie’s ears.
Clean up could come later, once he caught his breath, Donnie decided as he laid back, just holding his twin. They needed to wait for the genius’ cock to relax enough to release its hold on the slider’s womb anyway, then he would clean up, take his twin to bed, and no one would even know about Donnie’s dark little secret.