Title:- Your own worst enemy

Pairing:- Kasuka x Shizuo

Rating:- M

Warnings:- language, violence, hint of non-con, incest, yaoi, omegaverse.

Disclaimer:- I don't own Durarara

Summary:- Kasuka was born cursed.

Requested by:- Nana

Don't!

Everyone had a hidden face, ulterior motives or something inside their heart that wasn't normal. Kasuka was no different. Clutching the evil seed in his chest, the actor leaned closer examining his mask for abnormalities. None. His stoic persona was in place and his eyes empty and dead. Safe.

It had been that way since young and hadn't changed. Not the way he feared. His emotions manifested through acting. That was his outlet. That was the way things worked, had to work. Or else he'd give in to the curse that plagued him. The face in the mirror wasn't his. That empty expression wasn't his. Beneath the surface a monster lurked wanting what it could never have and what he'd make sure it never got.

Kasuka thrust himself away from the mirror unable to look any longer. His eyes weren't as empty as everyone assumed, they held desire, dangerous desire that would strip him of morals. After all animals didn't know the meaning of no.

Alpha meaning dominant. They existed. Some readily embraced their curse and others like him ran far away to escape it. Kasuka had run from himself but fought every step of the way. What he didn't understand was why there wasn't a drug to help keep the beast in check. The omegas had them, suppressors to keep their pheromones hidden and stop their heat.

Omegas were the unlucky ones. One bite from an alpha and they were bound for life. They were just like a woman but the heat cycle was choking seducing any alpha to take them. How did he know that? Because he'd been born into a family with an omega for an older brother. He'd seen the pills, witnessed the heat and had ran as far as he could.

Kasuka clenched his fists. It was enough. It was over. As long as he stayed away from omegas he'd be fine. He could abstain.

x-x-x

Kasuka sighed dropping his hand from the wheel. Traffic. Just great. It looked like there had been an accident just up ahead. Leaving his car where it was the actor climbed out feeling rebellious and bored. Bored meant thinking and thinking produced thoughts he shouldn't have.

So he didn't stop. Couldn't stop. Walking running, hell crawling if he had to. Kasuka closed his mind down and kept moving. His nose twitched his inner beast recognising the pheromones of an in heat omega. Kasuka trembled. It was an alleyway. Probably some careless omega forgetting their pills. He should have stayed in the car.

Did you know omegas had a unique scent, each one different? Kasuka swallowed thickly recognising the scent. It was the time he had finally decided to fight back against his curse.

Already running he caught sight of two figures- alphas- crouched over a third figure. Shizuo. Kasuka ran faster barrelling into the first. "Stay away." He growled not recognising his own voice.

The two alphas snarled back lost in his brother's pheromones. They were normal salary men by the looks of things. Strange since most alphas coveted the top spots.

Kasuka had already suffered his brother's heat once, so he had the advantage forcing his body to move and use the self defence he'd learned. It was like taking care of drunks. But finally the two alphas fled and Shizuo was left with the biggest monster. Him.

Kasuka grabbed the wall leaning over his dazed brother. Taking in the ripped clothes and the cheeks on view Kasuka growled. Close. Too close. Why hadn't Shizuo taken his pills? Or maybe he had? Either way the pheromones were too strong of a mating call. Eventually someone he couldn't handle would come along.

Someone else needed to be here and not him. Another omega. Kasuka frowned. He didn't know anyone else and time was running out fast. What if he accidentally called an alpha for help? What if that Orihara nuisance got wind of the situation and exploited it?

There was no other choice. The only one that could keep his brother safe was him. That was a huge joke on him. The instant Kasuka rested a hand on Shizuo's shoulders, he was hit in a increased dose of pheromones. But Kasuka had been battling those for years, so despite his mask slipping and his nerves becoming frazzled under his brother's allure, Kasuka fought the monster that resided inside him. His hand gripped the near unconscious omega- thank fuck for that if Shizuo whispered his name in this situation he'd be lost- lifting the heavy body from the ground.

Shizuo went over his shoulder like a sack of potatoes. Moving as quickly as possible Kasuka carried his brother back to his car and dropped him in the back seat. The boot would have been handier but already Shizuo's scent had spread penetrating his senses and the leather seats. He'd need a new car.

Kasuka hurried into the driver's seat looking down at his erection stifled by his pants and tight briefs. He wouldn't touch it. Not until his brother was safe and out of danger, away from him.

Nothing had changed in the traffic situation. The annoyed horns had started blowing and some people were leaving their cars to rest on the side of the road. Adjusting the mirror Kasuka swallowed taking in his brother's debauched appearance. Clothes torn and barely hanging onto his body, face flushed and the scent. Kasuka couldn't help himself inhaling a heavy draft like an addict with withdrawals.

It was a heady scent. One that made his cock strain and his senses dull. Kasuka gripped the steering wheel looking away from his brother. What face was he making now? Were his eyes showing the monster within?

More people were leaving their cars, only these men weren't joining the families or women at the side of the road. They were staring at his car and walking over as if enchanted by a siren.

"Damn it." Kasuka cursed flooring the car and breaking every road law going. He'd pay for it. Maybe through the tabloids or the police at his door. For now he needed to get Shizuo to safety.

x-x-x

Stupidly he drove back to his own apartment, inhaling more of his brother's pheromones as he lugged Shizuo into his apartment and dropped him in the hallway and again before they reached the bed.

Kasuka shivered hugging his mid section at the sight of his brother spread out across his bed. A personal fantasy of his and a dream come true. Licking his lips he took a step forward reaching out to expose Shizuo's lovely neck that had his teeth throbbing as much as his dick.

Shaking his head, Kasuka pinched his arm hard slamming a hand across his nose so fast he got a nosebleed. Backtracking he closed the door his hand refusing to leave the handle.

Don't.

Not after his hard work. He hadn't given into his affections since he'd first realised. Just because his brother was in his bed and in heat, didn't mean he should act on them.

Kasuka forced himself to led go losing the battle with his inner demon. The door creaked open and there was his brother still in heat writhing around uncomfortably and letting out more pheromones by the minutes.

No. Don't!

Kasuka clutched the handle fighting back. He wasn't going any further. Abandoning his bloody nose Kasuka unbuttoned his expensive jeans and unzipped the fly. Exposing himself he ground against the smooth door letting his imagination run wild.

Shizuo weak and panting before him, calling his name with watery eyes and those come fuck me pheromones. His name on those plump swollen lips. Kasuka groaned grinding hard into the wood his brother's whispered name upon his lips.

"Nii-san." He groaned rutting harder against the door. His brother was just on the other side. Kasuka yanked the door shut slamming as hard as he could, his hips continued to roll and snap back. "Nii-san."

Pulling away Kasuka dropped his legs unable to support him. Sliding down the wall Kasuka looked at his angry cock standing straight. If he stayed outside the room he'd be safe. Shizuo would be safe.

x-x-x

Kasuka knew he needed to get the medication to his brother. He'd managed the first dose. Now he just needed to get the second in. Except now his room was a war zone and if he went in there he'd quickly be submerged drowning in his brother's pheromones. But that was what happened when he couldn't open the window. Not if he wanted alphas trying to break in.

Kasuka looked into the mirror and what stared back was terrifying. His mask was cracking, his carefully sealed emotions oozing through. And his eyes. His eyes revealed the truth, what sort of person he was and just what he wanted to do to his brother.

With a sharp tug the mirror came crashing down shattering all around him. Kasuka paced becoming dizzy. He needed to get out. But more than anything else he needed to get that second dose in.

His dick wasn't going down and nothing was working. Jerking off, cold showers nothing. Kasuka had changed into something a little less tight but his cock still strained.

Again his eyes flickered to the door as they had been doing every few seconds. Kasuka clutched the injection stalking towards the door with a cloth tied over his mouth and nose. It wouldn't do much but it was another small defence against his inner demon.

He left the door open recoiling against the frame as the wave hit, calling to his base desires. Kasuka clenched his fingers in the wood taking slow breaths against his hand.

Shizuo was awake now, looking dazed and horny, straight at him. Kasuka flinched what was left of his blood joining the rest in his engorged cock.

Pushing through Kasuka felt sweat drip down his back, his teeth throbbing in his mouth, pulsating with the wish to bite. Still he moved forward as far as he could get and tossed the injection on the bed.

"...Nii-san." Kasuka called thickly his heart racing. "You're in heat. Inject yourself."

Shizuo continued staring at him, momentarily glancing at the injection. Kasuka let out a sigh of relief seeing the cure in his brother's grasp. He'd forgotten something. Shizuo's strength. It wasn't deliberate but his brother crushed the casing in hand.

Kasuka stared wide eyed watching the liquid soak into a puddle on the bed. Shizuo watched too before turning to him and eyeing him in despair. "...Kasuka?" His brother whispered hoarsely.

Kasuka had never heard anything so silky or seductive. Not even his on screen co actresses. Staggering back he reached around for anything to anchor him, to hold him back from defiling his brother. His fingers swiped through thin air on either side.

"...it's hot." His brother rasped crawling forward. Kasuka swallowed staring at the expanse of skin on view, Shizuo's nipples hard pebbles. His gaze dropped watching as his brother tore the remains of his shirt away and did the same to his jeans.

Kasuka stared. He had dealt with half naked and now his brother was showing it all. "...Kasuka?"

No!

Kasuka backed away but his feet were locked in place and Shizuo was trying to get off the bed, falling back with a soft mewl.

"...Kasuka. It's hot." Shizuo called to him reaching out a hand.

Kasuka traced his brother's body with his eyes. The slight muscles, the broad shoulders despite an average frame. Long graceful legs that didn't seem to end.

"Kasuka?"

No. Don't. Stay away.

Kasuka took a step forward and then another, his instincts overwriting his thoughts. Kasuka could feel his will being cornered and locked in a cage. It was his body but he wasn't in control.

Don't.

But he was smiling, lips twitching through his fallen facade. Kasuka was a helpless voyeur, zooming onto his brother as his body moved closer his legs hitting the end of the bed.

Shizuo reached out and touched him begging for help. Kasuka touched back one knee pressed on the bed.

Don't!

But it was already too late.

End