Chapter Text
When Katsuki began expressing, he’d been lucky enough to be home alone. It had been humiliating enough to even just realize he was an omega on his own. He couldn’t imagine how much worse it would have been if someone else knew.
He was thirteen at the time, birthday only a week prior. His parents were out — His mother on errands, his father at work — so his initial plans were to leave before they got back so he didn’t get roped into any chores. He’d been finishing up some math homework beforehand (if his grades fell, he’d have a hell of a time getting into UA later) when the scent hit his nose. It was a mix of brown sugar and cinnamon, warm and sweet. At first, the distinctly omega smell made him think someone else was there. He’d put down his finished worksheets and began searching the house, on edge. He was about ready to pounce on an invader.
He’d then started to realize that the scent was equally strong everywhere, no matter where in the house he went. A sinking feeling had entered his stomach. He immediately denied the possibility to himself. There was no way Bakugou Katsuki was some pathetic omega. He was better than that. However, when he brought his fingers up to the aching spot where his glands would be developing (they’d been in pain for a few weeks, a classic sign he’d been close to expressing) and then sniffed them, his worst fear was confirmed.
That sugary omega scent was coming from his own damn body.
He quickly followed his first instinct, which was to hide it. He found some scent blockers in his parents’ personal bathroom — His mother’s box for alphas, and his father’s for omegas. He took one package from each and stalked off to his room. He figured he’d be able to hide the smell with an omega blocker, then put an alpha blocker over it to make it seem that he expressed as one.
He opened up the plastic packaging of the omega blockers first. They fell into the floor as the wrapper was torn apart. There came as two white circles, covered in ridges and grooves and about two centimeters thick. Their diameter was similar to that of a five-yen coin. He clenched his jaw at the sight of them. He wasn’t supposed to have to use these. This wasn’t how it was supposed to go…
He screwed his feelings down, however, to focus on the task at hand. He needed to make sure no one figured it out. He removed the paper that preserved the adhesive of each blocker and stuck them on carefully. His father wouldn’t notice one omega blocker missing, but if Katsuki fucked up and had to take multiple packs, he could be found out.
He next reached for the alpha blockers, which were contained in black foil. He opened up the wrapper and dumped them into his palm. These were a bit larger, maybe a few millimeters so in length and five in thickness. They took on a diamond shape and were smooth, save for a single raised ring in the center. The issue would be that he couldn’t just place the blocker atop the first. Each contained venting and filtering systems specifically designed to keep pheromones in while still allowing the gland enough air to not become infected. (Well, any decent blocker, anyways. Cheap-ass things might not, but almost everyone agreed those were dangerous.) What’s more, Katsuki’s family always got some of the best blockers on the market, meaning the filtering was done with complex tech. He needed the alpha blockers hollow to put them over the omega ones.
He began digging around in his desk for scissors. He figured he could use them to remove the insides of the blockers. When he found a pair, he stuck the blade between the mechanisms and the walls of the blocker. It successfully slid in, surprisingly without resistance. He was able to pop the interior out by applying pressure to the scissors as though they were a lever. He did the same to the second one before placing them over the omega ones.
His eyes slowly made their way to a mirror. He didn’t look any different. The scent was gone. All evidence would be gone once he hid the blocker waste.
But, it didn’t matter, not really. Katsuki knew. No amount of hiding would change the truth. He wasn’t really an alpha.
He wouldn’t let himself cry, though. All because he was a pathetic omega didn’t mean he had to act like one.
So, Katsuki hid it. He went the extra mile. He went out for his omega needs in mask and hood so no one saw him purchasing them. He got bottles of some of those artificial alpha pheromones from an omega speciality store and marked his room with them, let a thin veil of the scent (oranges and wood, similar to his mother’s) linger on his belongings. He was sure to always conduct himself in a manner that screamed alpha. He suppressed every instinct.
No one knew. Not Deku, not his family. He intended to keep it that way. His omegahood was a source of shame, and his resentment of it only worsened when Deku eventually expressed as an alpha. Fucking Deku, of all people!
Was there something wrong with Katsuki? Why couldn’t he have expressed properly?
It had happened soon after they moved into the dorms a month or so ago. Now, Deku’s stupid fucking rain and catnip scent lingered everywhere. Katsuki couldn’t even enjoy it in a moment of weakness like other alpha scents. One whiff of it and he wanted to murder something.
Which was exactly how he felt now.
“You good, man?” Kirishima asked, stalling his previous intention of asking Katsuki about the homework. “You’re looking kinda mad…”
“I’d be better if a certain fucking nerd stopped marking everything with his scent,” Katsuki barked, glaring in Deku’s direction. (The alpha was oblivious to this, talking to Uraraka and Iida without a care in the world.)
“You’re one seriously territorial guy,” Kirishima remarked, raising a brow. “I’m the youngest of five alphas, yet all of us combined are more chill…”
“Shut the fuck up, shitty hair!”
Kirishima laughed, putting his hands up. “Alright, alright, sorry, Baku-bro. Anyways, you mind helping me out in English? I’m still pretty bad with pronunciation, and we’ve got that oral presentation Monday…”
“Fine,” Katsuki gritted out. “Can’t believe you still need me tutoring you, fucking idiot…”
“You sure it’s just your usual vendetta against Mido-bro? You seem extra grumpy the last few days.”
It was because he still got the mood swings, aches, and fatigued of heat, even while on suppressants, and he was approaching his heat season. Not that he’d vocalize that.
“Just fuck off,” Katsuki spat, his equivalent of saying I’m fine. “I’ll meet you in your dorm tomorrow at four. Be late and I’ll kick your ass.”
“Sure.” The red-headed alpha nodded. The cheap blocker he wore slightly lifted with the movement, filling Katsuki’s nose with that relaxing scent of soil and salt…
He turned away and left before the omega in him could react too much. He’d hid it this long. He wasn’t letting one alpha stop him now.