Chapter Text
When Leo found out Donnie regressed, he really upped his supportive brother™ moments.
If Donnie was overstimulated, Leo was the go to guy. Rattles and chewelry and pacifiers became part of the selection of stim toys he kept spares of for Dee.
And hey, now Leo knew why sometimes he caught Donnie babbling to himself while inventing, not that he jugded before.
This was all... kinda nice, actually.
It felt like after the invasion, while him and Raph and Mikey grew closer—He grew apart from Donnie... Granted, that's also when Donnie probably started regressing, and therefore self isolating... he felt a little bad about it actually...
But now Leo could be there for Donnie again!
He used to watch Donnie work on his battle shell or S.H.E.L.L.D.O.N at the latest of nights, and now he watched over Donnie in general when everyone else was asleep.
And Donnie and him, before the invasion, sometimes stayed up real late to watch crap TV shows. Now it was things like Octonauts and Bill Nye the Science guy. And Donnie would build himself a nest and drag Leo into it. (Note: Leo was not allowed to help with nest building, that resulted in upset autistic toddler hissing.)
And it was fine—Minus the fact that, while Leo played it cool in front of Donnie, each minute they spent in the open caused anxiety to flare up in the slider. At a moments notice, they could be caught. And Donnie would blame Leo, and Leo would lose his brother again and everything would suck.
Luckily, he's a fabulous liar.
The first little lies, nobody suspected. Why was there a sippy cup out? Oh, Leo saw Donnie was cleaning some junk out of his room, probably needed more space for some big brain invention. (Leo had to dig it out of the trash after Mikey shrugged and tossed it, he washed it and never told Dee.)
One night Raph walked in on Donnie and Leo cuddling watching some toddler show on YouTube? "Raph, Hermano, big guy—you know I have auto play turned on! We just fell asleep making fun of this stuff." And Raph joined in the turtle pile, which was nice.
April never really questioned anything out of place she saw, honestly, Leo suspected she already knew. And Splinter... didn't notice in general. For once, his lack of parental awareness was awesome.
Draxum apparently knew, but that was a whole other create of canned worms Leo was not unpacking. Not today, Satan!
There were a couple close calls here and there. The worst one Donnie was there for, Mikey was vacuuming and found his pacifier he'd lost a day eariler. Honestly, Leo was kind of grateful—Donnie threw a fit the size of an extra extra extra large pizza when he couldn't find it.
(It was more akin to Donnie panicking severely and lashing out by proxy now that he thinks about it...)
But, Neon Leon's got this! He just lied again, and Mikey seemed a little suspicious, but it worked!
And Leo was doing good. He was protecting something he felt obligated to, and he wasn't going to ruin this.
And he was only a teeny tiny little bit stressed about making sure he wasn't responsible for messing up his brothers one healthy coping mechanism...
Then Donnie was missing and what the heck.
It was two AM, Leo had come to Donnie's lab like he's starting doing routinely, his sippy cup had been left under Leo's bed, so he wanted to return it before Donnie lost his mind trying to find it.
Knock knock. "Psst, Dee? Lemme innnnn." Leo whispered, yet no door was unlocked and no reply to be heard. "C'mon, buddy? Don-Tron? Mi Amigo?"
There was no response.
Leo rolled his eyes, putting in the secret little override code. It was something he asked (kinda told-?) Donnie to add, after a certain incident involving pancakes, panic attacks, and lockdowns.
The door hissed open, and no light met Leo's eyes. Dark, the lab was dark and empty, he put the sippy on a near by table. "Don?"
He wasn't in his room, either. Completely confusing the slider, the living room maybe?
He walked, tip toeing as to not wake anyone else. This whole place echoed like crazy. "Donnieee?" Leo's words dragged out in a long stretch.
"'Nardo?"
Leo turned to the kitchen, in hindsight, how did he miss this?
Donnie was in the (dark) kitchen, it smelled like brownies. "Why are you sneaking around all suspiciously? Did you break something again?" He deadpanned.
"Oh-" Leon relaxed. "I dunno man? I didn't know if you were, yknow-" He made a little gesture with his fingers. "I didn't wanna wake anyone up?"
"...Fair point. I made you brownies." The softshell slide a pate of perfectly cut, dark chocolate and rainbow sprinkle brownies to Leo. Who blinks in confusion.
"Uh- what?"
"Brownies, dumb dumb." The purple clad turtle began to clean up the kitchen, "I needed to show you a gesture of gratitude, and... ugh, mere 'Thank yous,' are below my superior thanking skills!"
Leo took a bite and sat down, they were pretty dang good—Well, baking was technically a science, so made sense Donnie took that on too. "Pft, well, it isn't below me, thanks Dee."
A slight smile tugged at Donnie's face, he seemingly wanted to add more, but words caught in his throat.
The two were in silence for a minute or two, Donnie wiping up his mess and Leo savouring the sugar filled physical manifestation of gratitude.
"...I... appreciate... what you've been doing for me, Leon." Donnie finally spoke as tone dropped lower.
"Like, taking care of you? Don't sweat it, hermanito. It's great."
"Well, yes, that too... But, I do appreciate you not... blabbering, about it either. I doubted your ability to keep secrets, but alas, you've proven me... wrong."
Leo's face couldn't help but twist into a smirk. "Donnie, the Donnie, proven wrong, by moi? Hold on, can you repeat that? I wanna make it my ringtone." He held his phone out into the softshell's face, who groaned and playfully shoves him.
"Once again, my sincere moment has its spotlight stolen." He dramatically exclaimed, but Leo could tell he was trying not to smile.
Leo stuffed another brownie into his mouth, they were actually pretty good. "Seriously though, bro, I got you. Okay? Your secret? Yeah, it's safe with me."
Donnie got finished cleaning, taking a brownie for himself.
"...You didn't abandon me, either."
"Wha-"
"Don't what me, 'Nardo. You didn't get weirded out, and leave me... I appreciate that too... Dear Galileo, it takes a lot of mental energy to say this all-" He sighed. "...I... am here for you too, okay? Just... if you ever... go small yourself, or... whatever you do, I will also be there. Just... tell me what you need."
Leo let his body relax a little, not a lot, but a little. As if he'd gotten so caught up in making sure Dee was okay, his own needs were buried. Well, he did that anyways, but still.
"Heh... thanks, probably not my thing, but who knows? Maybe I'll take you up on that offer next time my ego is bruised or-"
"'Nardo I swear to GOD I'm trying to be sincere!" Donnie immediately exclaimed, cutting him off.
"So am I! My ego is a very important part of my identity!-"
"LEO!"
And the two dissolved into not so quiet playful banter. Which may or may not have awoken one or severel family members, which may or may have not been happy about that, but luckily brownies are a universal bribe for not getting upset.
Yeah...
Leo and Donnie would be okay.