Iruka was wide-eyed, staring up at the legendary jōnin, when he whispered, his voice shaking, “It’s okay, Kakashi-sensei. I know I’m not an omega, but I can – you can –”
Blood dripped on his face. He tried not to flinch; he kept his hands tightly clutching Kakashi’s flak jacket.
He had never seen his friend as he was now. Truthfully, Iruka barely remembered Kakashi was an alpha most days. During their entire friendship, the man had been unresponsive to Konoha omegas, never batting an eye at passing pheromones, never glancing at an omega in heat.
But now Iruka was flat on his back on the linoleum floor of his classroom, his gaze stuck on the gruesome head wound in the thick of Kakashi’s silver hair. Only a few inches away from the still-seeping cut, he had nowhere else to look. He certainly wasn’t going to close his eyes with Kakashi forcibly pinning him down on the ground. Their faces were so close Iruka could feel the man’s hot breath pouring through his mask. He could see Kakashi’s dilated pupil – the slight difference between pure black and dark grey – trying to focus down on him but failing over and over again.
Another fat blood droplet fell from Kakashi’s injury onto Iruka’s scarred cheek.
The alpha above him was in heat.
He was so very much in heat, it had Iruka, just a beta, feeling dizzy.
Iruka was trying to remember how they even got here. Kakashi-sensei, his friend, permanently unbothered and even insensitive, had knocked him down onto the classroom floor and forcibly held down Iruka’s shoulders. Just a moment earlier, Iruka had been outside with Suzuki-san, speaking to the woman by the playground, discussing how her son seemed to be presenting as omega like her. He had been reassuring her that, although he himself was a beta, he knew a great deal about alphas and omegas, being both a teacher and friends to all three sexes. Little Mako would have plenty of shinobi to look up to – including the beloved First Hokage himself! – and he would never be bullied at the Academy, not under Iruka’s careful watch.
Without the least bit of warning, Kakashi had silently materialized on the other side of the playground. The unexpected presence of his friend attracted Iruka’s attention immediately. The jōnin’s aura was bad. He was leaning far, far left. His hands were both shoved into his pockets. He was staring straight at Suzuki-san.
Who… Iruka suddenly noticed… was going into heat. She was an omega going into heat.
In front of what Iruka rapidly realized was a heavily wounded alpha jōnin returning to Konoha from a mission.
He stepped in between alpha and omega, ordered Suzuki-san to go home, and…
Kakashi had abruptly appeared in front of him like a black-shadow specter from a horror movie. His hitai-ate was a little askew; his whole demeanor was darkened, disturbed. An enemy had landed a sword-blow above his left temple, cutting into his scalp and flooding his silver hair with bright-red blood. His high-necked blue mask had slipped down some. Kakashi’s revealed eye was roaming about Iruka’s form as if he was trying to take in all of the man but finding it impossible.
The jōnin seized Iruka’s flak jacket, lifting him right off the ground and into the air.
The next second, they were standing in Iruka’s classroom. Still fearfully soundless, Kakashi had shoved him to the floor and then restrained him before Iruka could even comprehend that he’d been taken upstairs in a shared Body Flicker jutsu.
And now Iruka was holding onto the two front pockets of Kakashi’s flak jacket like they were dual lifelines. The sounds in the classroom seemed deafening: the jōnin’s harsh breathing through his mask merged with the intense pounding of Iruka’s heart in his ears. The alpha above him was exuding all sorts of pheromones that Iruka had never, ever associated with his friend, Kakashi Hatake. Being a beta, he only occasionally witnessed alphas in heat – and he was rarely so close to one without someone else’s instantaneous intervention.
But he knew the complex scent saturating the atmosphere.
Iruka recognized the hot flush of sunburn-red on Kakashi’s slightly exposed cheek.
He could feel the jōnin’s instability as it shifted him in turn. Although unreasonably silent, Kakashi had no control over his body’s movements: he was trembling from top to bottom and taking Iruka along with him. Along with witnessing uncharacteristic shakiness, there was something else that Iruka had never experienced before with Kakashi.
The very pronounced hardness pressed against Iruka’s thigh.
He felt his mouth going dry at the sensation as he stared up at Kakashi’s blushing but mostly concealed features. Honestly, Iruka hadn’t thought the jōnin ever became aroused: he’d always imagined him as both aromantic and asexual. When Iruka had gone on dates with other betas, Kakashi had never appeared to notice, even the time they accidentally ended up in odd conversational three-way at Ramen Ichiraku.
But he had been wrong, very wrong.
Not only did Kakashi Hatake feel arousal, he was sexually fixated on Iruka - at least in this moment. His heat as an alpha was making him thoughtless, reckless, crazed. He was someone else, he was out of his mind and totally primal in his instinct. He couldn’t keep still, he couldn’t even focus fully on Iruka laid out underneath him.
He would go after Suzuki-san - any alpha would – she was an omega in heat, her pheromones screaming for him to find her and fuck her and make her his.
Worst of all, Suzuki-san didn’t have a mate.
If Kakashi bit her…
So Iruka had shakily reassured him, keeping their bodies intertwined, trying to prevent his friend from losing it on someone else:
“It’s okay, Kakashi-sensei. I know I’m not an omega, but I can – you can –”