“You are an Omega, aren't you?” declared Deidara, making Obito stop walking. The tall man turned back and looked at the smaller alpha with a bewildered expression. Good thing he was wearing his orange mask because he must be making a stupid face. Obito wasn't an Alpha, like most Akatsuki’s members, but just a simple and ordinary beta. If he would have been an Alpha he would be a better Madara. The old man's words, not his. If he was an Alpha his whole life would have been better in retrospective, the clan Uchiha would have respected him more and Rin might have loved him instead of kakashi.
“I'm not an Omega senpai, I'm an-”, Obito answered in Tobi's pinch voice, trying to understand how such a misunderstanding happened in the blonde’s head. Obito was way taller and more sturdy than your average beta, not to mention he didn't behave like an Omega at all.
“Stop! You are not an Alpha, it doesn't matter how many times you said it. I know you aren't an Alpha, all of us know.” Deidara interrumpes, raising a hand, glaring at his teammate.
Obito tilted his head and pretended to be a confused puppy, while he thought when did he pretend to be an Alpha while playing Tobi. Nope, no such a thing happened. He decided his Tobi alter ego was a Beta, just like himself, so why did Deidara think he is an Alpha? Could it be that he accidentally played the Alpha card in this disguise? Even worse, when did he act like an Omega?
“But I'm not an Alpha, Deidara senpai”, Obito finally said meekly, when Deidara stopped his weird explanation of why Tobi wasn't an Alpha. Who knew there were so many social cues and signals between Alphas and Omegas. Good thing both Nagato and Konam were betas and were ignorant of the weird world of pheromones. Of course beta could tell somethings about pheromones like feelings (strong ones), but not all the weird sexual bullshit between the other two second genders. People said Alphas were better, but Obito was sure Betas were way better at being ninjas.
“You are not”, said Deidara, suddenly unsure of what to say. “You are not! What was the leader thinking when he assigned me to be an Omega's babysitter? Eh!”
“I’m babysitting you senpai, no the other way-”
“Ah? What are you saying! I'm always saving your lame ass! Fucking Omega” Exclaimed Deidara entering Obitos personal space. And trying to kick him in the butt only to stop a few centimeters. Just realizing he was about to hit what he supposed was an Omega. Which was weird? They were criminals, they punched women or Omegas on the face if needed.
“Deidara, I'm not an Omega” Obito said, fully showing his height and trying and failing to sound serious while using Tobi's voice.
“You never do a thing when we are on missions!”
“I'm supervising!”
“When we visit a hotel you always built a nest”
“I don't do that!”
“Of course you do! You make a weird thing with cover sheets and cushions!”
“ I JUST LIKE TO BE COMFORTABLE and I was cold, nothing else!”
“You are always cold, like a fucking Omega!”
“I'm not Senpai!”
“Then why are you covered head to toe in clothes? I had never seen your face or any place of your skin!”
“You can see my toes!” Tobi declared moving his toes.
“You know what I mean, it's almost like you were protecting your glads from everyone!”
“Everyone does that, senpai!”
“No, they don't! All Alphas left their gladules uncovered, open to the air to scent what they want, while betas don't care!”
Tobi raised a finger and stayed quiet, unsure of how to counteract Deidaras’s argument with something stupid. He couldn't say he was disfigured and nothing especially fun came to his mind to distract the alpha from the true. Deidara was right, the only alpha he knew who didn't show his body was Kakashi but he only hides the scent glands on his neck. And betas, for etiquette, cover some scent glands but not all of them. Only Omega's covered their whole body, especially their necks.
“I like these clothes, they make me look cool”, repeated meekly.
“Ha, keep telling that to yourself. Um.” Deidara said proudly, realizing he won the argument. “I have never seen you scent anything, even betas can do that”.
Deidara was right, betas didn't need to scent but did it when they needed to interact with Alphas and Omegas.
“Maybe I don't have scent glands, senpai” Obito confessed. Human glandules were on the left side of the neck, Obito’s were destroyed when the boulder fell over him and the weird thing making his left side smelled like a plant more than a human.
“You smell sweet, too sweet to not be an Omega.”
“Maybe I use perfume”, Obito countered. Of course the excuse was weak.
“Only Omega's smell like flowers, just like you”, Deidara sniffed Obito. If the Uchiha wasn't under a disguise he would have punched the Alpha on the face, sniffing others was rude even between betas.
“Are you saying you like how I smell?”, Obito said between teeth with a disgusted smile, trying to sound playful.
“On your dreams, um” Deidara huffed, taking to steps away from the beta. Apparently offended, Obito suggested such a thing.
“And what if I'm an Omega? What senpai is gonna do?”, Obito said, using his Tobi voice but sounding a little like the sour and unhumorous man he really was. Deidara looked warily at his partner, before showing a shit eating grin.
“Are you angry I discovered your little secret?”, Deidara was full of mischief. And Obito, he rolled his eyes and decided that if Deidara decided to think something so stupid he was going to allow it. He was going to have fun with him
“Oh! You discovered me, senpai, please don't say to the others!”, Obito cried, throwing himself at Deidara, who accepted him in his arms like the poor little Omega he pretended to be. “And I will always cherish you as my favorite pup!!”
“I'm not a pup!” Deidara cried, pushing Obito away while Obito laughed with a pinch voice.
===================
Because of his ex teammate, Obito learned to make a nest, he always did one each time he had an opportunity, and he began to act like he supposed an Omega would. He was unbearably nice with pups, so he decided everyone younger than him in Akatsuki was his pup. He even learned to purr like he remembered his grandma used to do. If he remembered correctly Omegas between the Uchiha were rare and all of them purred to their pups. He was so convincing, or unconvincing, Nagato and Konan threw him weird looks while Itachi pretended he watched nothing. Of course Itachi knew he was a fake, after all his mother was an Omega and he knew how they were supposed to be. Deidara and Hidan suffered his Omega like actions, while Kakuzu ignored him and Kizame humored him. Zetzu hated his little play but went with it. Everything was fun until things became serious, the plan had to progress and people began to die.
Then there was no more Hidan, Kakuzu, Deidara or Itachi to play with, and his Tobi persona wasn't needed anymore. Madara came back, and with him, pretending to be an Alpha. Then Nagato and Konan turned against him and had to die, fucking traitors. Then the new Akatsuki came, Sasuke and his team, Kabuto. Then Kisame died. Then the war happened.
And in all that time, when he was playing to be a big bad Alpha against the words, when he was alone in kamui he made a giant nest full of the things of those who used to be Akatsuki. Even Konan and Nagato had a place on his enormous nest which sometimes suffered damage from using his technique.
============
When his mask cracked and his identity was discovered, and Kakashi discovered the trick behind kamui, they traveled to their secret dimension. But instead of falling into an empty block and having an epic battle full of feelings about the past, they fell on his nest.
“What is this?” Kakashi exclaimed, confused, trying to stand up on the unsteady surface.
“Don't get distracted,” Obito hissed, full of adrenaline. His nest was full of kunais, broken pillows and disordered clothes and the intant part was where Obito fell.
“Is this a Nest?” Kakashi insisted with a weird tone of voice, looking at Obito with huge eyes. He sniffed the air.
“Who cares! Fight me you asshole!” Obito tried to land a kick on the Alpha but he jumped to the right, to a monticle of green clothes.
“Is that my flat jacked I lost two years ago?” he asked, lifting said jacked.
“Stop it! You are ruining everything!” Obito hissed! Trying to stab Kakashi without killing him neither ruining what was left of the nest. He was a Beta and he didn't need a nest, but it was filled with so many things he liked that he was unwilling to use fire jutsus.
“Stop, Omega!”, Kakashi growled and a flux of pheromones punched Obito on the face. In a kick move Kakashi captured both of Obito's wrists and kicked his feet, throwing both men at the soft surface. “Feisty Omega, I'm going to fill you with so many pups that you will wish never began this stupid war,” Kakashi’s chest rumbled and Obito's whole body shivered.
“Hey! Let me go, bakashi! I'm not an Omega”, Obito struggled weakly, feeling incredibly aroused. His face was flushed and he wished to be an Omega for a sec.
“Good thing I don't care”, Kakashi smiled with his eyes. “I will make you my Omega”.
“Oh my god” Obito exhaled.