Work Text:
“Shit!” Donatello cries, backing away from his desk as the test tube explodes, but he’s not far enough away to escape. The black goo coats him, sticks to his skin and his gear like it does to everything else in his lab.
“Fuckfuckfuckfuck!” The tap runs, and Donnie shoves himself under it quick, trying to wash the specimen off of his skin before any damage is caused. Even despite his precautions, his anatomy makes it near impossible for him to stay totally covered; parts of his legs, arms neck and face still exposed to the air during his various experiments. And now he’s probably gonna pay for it.
Well, he hopes not, but hope’s a fickle thing. The stuff won’t budge, even when he tries to scrape it off with a sterilized rod. It’s like it’s solidified on his flesh, which is impossible considering it’s chemical properties and the fact that Donnie can still feel it as a liquid. Wet and sticky like honey.
He scrubs at it again, and this time it seems to move; trickling down his arm slowly. He perks up at that, continuing with more vigour, humming away whilst thinking of a way to clean the rest of this mess up. Perhaps some hydrochloric acid will wear it off of his clothing?
Rivers of it drip down his skin, and he’s sweating, very uncomfortable all of sudden. He raises his other hand to his head, dabbing away at the sweat, frowning at the wet texture of his hand. His gloves weren’t–
“Oh no. No no no.” It’s too late a realisation. Donnie’s other hand - no, his whole arm, has been enveloped by the goop. Black, rubbery and shiny, and Donnie can barely contain his fear. How could he not notice it happening? How?
Fear grips him, and he turns to his other hand, which is still buried in the sink. Sure enough, it’s covered too, right up to his elbows.
“Oh god.” He feels numb, quickly scrambling around for something – anything, to help. The heat’s unbearable, and without thinking he discards the rest of his clothing, whilst he searches, knocking over vials and beakers as he goes, finding his rubber coated arms resistant and clumsy to his movements. “Please, please, plea– No!”
It’s spreading! Oh shit! It’s spreading all over him! His crotch, his stomach – quickly climbing up to his neck and – shit! Shit! He needs help!
“Hel-mmpH!” He’s cut off as his head’s swallowed by the goop; his mouth and nose flooded by the stuff as envelopes his face, cutting off his sight and breath in an instant.
—
“Donnie?” The door opens, and Mikey steps in. It’s Mikey! Mikey’s here! Oh he’s waited so long!
Mikey prods forward, eyeing the carnage on the floor warily as he goes, completely unaware of his presence. “D? You okay? I heard you scream?” Yes. Yes he’s okay. He’s fine. Now that Mikey’s here.
When Mikey reaches the centre of the room, Donnie moves, closing in on his younger brother from behind and grasping him around the sides, taking in the feeling of that warm, delicious flesh.
“D-Donnie?” Mikey’s voice is tiny in Donnie’s ear. Weak, helpless. But Donnie can make that better. He’s so much better himself, now. He wants to make it good for Mikey, too. “Why are your hands all…rubbery? Are you wearing a costume or something?”
“Something like that.” Donnie husks, his voice not exactly his own; a sinister tone rings through; right next to Mikey’s ear, wheeling the younger around to face him. The look on Mikey’s face when he sees how perfect he’s become is so satisfying, that he has to lean down and touch it, feel what’s going to be his soon.
“W-What the fuck?” Mikey tries to pull away, but Donnie holds fast, shoving the younger turtle up against his desk. “L-Lemme go! Donnie!” Donnie just laughs, gazing at himself in the mirror of Mikey’s dazzling blue eyes, slick and shiny and black. All new.
“Now why would I do that, Mikey?” he purrs lightly, pressing his fingers down against Mikey’s crotch, feeling around for that sensitive slit that will give him his prize. “You’re mine, Mikey. I want you. I need you inside of me.”
As if to prove his point, his rubbery body opens up opens up, churning into an empty, sleeved husk of padded rubber. Mikey cries, tries to run, kick at him, but it’s useless. Donnie just flips him around, amused as Mikey gets pulled inside him, swallowed up by him.
His cock, fully rubber and black now, finds it’s way into Mikey’s ass, and he fills him up, locking him in place. Like a restraint. Mikey’s eyes are wide and he’s shouting, and it’s all so delicious to Donnie. To his new body and his warped thoughts.
“We’ll be one, Mikey~” he husks again, leaning down. His face parts, and Mikey begins struggling even more. “It’s useless, you’re already mine~” He runs a hand down over Mikey’s crotch, their crotch, now fused together, and pulls a blob of goop out of it – a rubber cock in the shape of Mikey’s own peeking out.
“N-No! No! No! D-Donnie! Donnie! S-Sto–mmmPh!” He smears it over Mikey’s face, covering it entirely, working it into his skin and silencing his brother with his own cock so he can finish his work. “Mmpppph! Mmmphooo!”
There’s a sickening squelch, and Mikey’s head is finally swallowed, absorbed deep inside of him. He grins, feeling Mikey’s warm body churning inside of him, still fighting as they merge into one. At last.
“Mine~” Donnie purrs again, and Mikey purrs with him; working their now exposed cock, glowing in their accomplishment and Mikey’s submission, and excited at the prospect of finding their next victim.