Title: Cosmopolitan

Author: vashsunglasses

Rating: T

Fandom: TMNT

Disclaimer: TMNT belongs to Mirage.

Summary: One Shot. Drabblish. Being the only scientist in the family, Donatello finds it easy to hide certain facts that are best kept secret. Genderfic.

"Hey guys!" Michelangelo cried out gleefully, running through the lair with a magazine in his fist and dodging a furious Donatello, "Look what I caught Donny reading!"

"Oh, lemme see!" Raph exclaimed, grabbing the magazine and then snickering when he saw the cover, "Cosmo! Don-san, you read Cosmo? What, are you gay?"

Donatello snatched the magazine away from his grinning brothers, "No I am not gay! It's research!"

Leonardo walked out of the dojo with Splinter, "What kind of research?" Leo asked curiously.

Donatello had always been the smallest of the turtles. Slight differences in physique that lead Raph to rib him about being effeminate, and lead to constant defeats in sparing matches.

He'd been only eight when a book on turtle anatomy found its way into the lair. The best way to contrast and compare anatomy with Red Eared Sliders was to look within himself, as it were, and he found nothing that matched the male physiology of either turtle or human. So he chalked it up to the mutation and left it at that.

Then came adolescence and his brothers began acting out in inexplicable ways. Changing in ways that both bewildered and frightened him because he didn't feel those same changes within himself. But he had always been smaller, so he chalked it up to a slower development and left it at that.

Then came his teens and he stumbled upon one of his brothers doing something in private that threw every assumption he had right out the window. And after blushing and apologizing and running to his lab to hide he considered what he had seen, and checked himself once again, and hoped that he had missed something. But no, at least one of his brothers had the male physiology of a turtle, and Donatello did not.

The idea horrified him. What if he was deformed? A eunuch? He had to test the others, to see if he was the only one. So under the guise of science (and with much grousing from his brothers and much blushing from himself) he examined them all, and came to the heart rending conclusion that they were all anatomically intact. Only he was different.

He couldn't let anyone know, so he made an effort to be as masculine as possible. Or at least he tried to, until his brothers laughed at him and asked him why he was acting funny. So he went with the effeminate professor excuse, and they seemed to buy it.

Then came the insomnia, and the stifling heat that made him want to crawl out of his own shell, and the claustrophobia that brought the sewer walls closing in. He needed to get out. Need to breathe the fresh air. Needed to settle his stomach that felt so bloated and cramped and tight behind his plastron.

So in the deep of the night he crept from the lair, searching, searching, for something he knew not. Only that there was somewhere he needed to be. Somewhere where his stomach would stop hurting and the muzzy heat would finally clear from his head. And when a breeze came down the dark tunnel he followed it to the ocean.

And in a sheltered alcove she laid her unfertilized eggs and buried them beneath the sand.

Everything she knew was wrong! He was wrong! He was a she! He made it only halfway back home to the lair before she threw up the contents of his stomach. And then she laughed with a choking sob at his earlier worries about being a eunuch. Apparently her well traveled and learned Master couldn't tell the difference between male and female turtles. In that moment, he wanted to die. In the next moment, she pondered the thought of perpetuating the species and vomited again. It was soon after that his brothers found her and dragged him home, where she was ill for several days with headaches as her entire brain recategorized itself. One thing she knew above all else, she couldn't tell anybody, not yet, not until she understood it fully.

"I'll tell you when I'm finished," Donatello said, giving her brothers an inscrutable glance. "Once I've got it all figured out you guys will be the first to know."

"Yeah, whatever dude," Michelangelo replied, bored already.

"You're so gay!" Raph cackled cheerfully.

"I am not gay Raph, and if I were you I'd remember who it is who gives the vaccinations around here!" Donatello said with a smirk, entering her lab, "Flu season is coming, and I'm the only one standing between you and a month of coughing."

"Leave him alone guys," Leo said sternly, "Donny will tell us when he's ready. He's the most dependable guy I know."

Donatello flinched.