Title: Impulse

Author: Metamorcy

Rating: M, just for safety

Summary: Tsuna sometimes really hated his werewolf bloodline and the inconveniences it would create for him. So the one day he forgets to take his medicine to hide his extra features from the human population, he ends up finding himself a mate by accident.

Prompt given by anonymous on tumblr: R27, werewolf au, mates. Werewolves are so rare that it is not a good idea to accept that you are a werewolf. Nana gives Tsuna pills to push his fangs, claws, omega eye color, etc down, but one day he forgets and has to run away without anyone noticing that he's a werewolf but Reborn does cause he is a werewolf too and an alpha on top of that. So love happens.

A/N: I took out the whole omega and alpha typing as it didn't quite fit with the story I had written down. Hope you don't mind (to the anonymous)

Tsuna really hated his annoying bloodline. He hated every little bit about it and how utterly maddening it could get. He wasn't human, not like the rest of the people in this godforsaken town, but a werewolf. Luckily, he wasn't like anything the humans thought werewolves were like with the whole full moon transformation or weakness to silver or they were demons. The only thing that could identify him when compared to a regular human was his additional attachments that would appear on his body: his bushy tail, claws, ears, etc. He looked more like one of those half-transformations compared to those complete ones humans believed in, not that he was complaining. He actually liked this form since it was easier to get around, if he covered his attachments well enough. The only thing he couldn't quite hide was his eyes. They would have an unearthly glow, orange in shade, while his mother had had more of a yellow.

However, appearances weren't the only differences between his kind and humans. Werewolves had superior physical strength and speed compared to the mortals, enough so that they could easily crush a human skull with their bare hands. Their high-speed healing was extremely convenient when injured, healing within a matter of moments instead of weeks. There was also their enhanced awareness, Tsuna's being enormously powerful and almost unnatural for a werewolf, that allowed him to sense everything around him with ease. Of course, Tsuna was a pacifist by nature and refused to get into fights even when getting bullied back in middle school. As he grew older, he became much better at avoiding people, using his abilities to his advantage and some of his strength to push them back (never enough to actually hurt).

As for the intelligence, he had his fair share, but it didn't help that he had inherited his mother's obliviousness to his bastard of a father's laziness. Luckily, hard work paid off and he paved his way into college where he was currently studying for a degree in financing.

Sadly, because his kind weren't exactly normal and more in the supernatural dimension, he had to hide his identity. Humans were never quite accepting of beings that were different from themselves and Tsuna took no chances in getting himself hunted and killed. He wanted to live a peaceful life away from the violence and be content with a mate that would love him dearly. He honestly admitted that he had some past crushes on some humans (a girl named Kyoko being the best of them), but that was as far as it went. He knew better than to push the boundaries any further than that.

As with his unnatural abilities and appearance, it wasn't wise to mate with anyone that didn't belong in their race. Sure, there were other supernatural beings out there that could work (like demons, angels, and even the vampires, who weren't their enemies by the way [the humans decided they were]), but it wasn't recommended because of the cultural differences. There was also the issue that if a werewolf found another one that was both appealing and alluring to their instincts, they would unconsciously act through lust and desire to claim the other as their own. That didn't always suit well with others they were currently dating. However, it didn't happen all the time and people still mated despite not feeling that burning connection (his mother being one of them).

Still, Tsuna didn't mind and continued to live his life as he always wanted to. He went to school, worked his ass off to get good grades, before returning home where his mother was to rest. It was a good, peaceful life and Tsuna loved it. However, he should have known better than to believe that it would last forever.

After all, today of all days, he had forgotten to take his suppressant pills to hide his features, something that was given to those young in age to keep their additional features covered until they were old enough to hide it on their own. It also helped to mask their scents from all creatures, not wanting to attract trouble. What had happened was that he had to rush out for his college classes, having woken up late after staying up to complete his homework and last minute projects. He had managed to finish everything in the nick of time, but that didn't mean he got his rest for that night. Still, because of his rush, he had opened himself up to being revealed to the world and it was only when his second class of the day started (thankfully turning in his homework and projects at the beginning of each class or online) that he realized with horror that parts of him that were usually kept hidden from the world began to appear.

The first thing that exposed itself was his ears and luckily his hair was extremely spiky and unruly enough to completely cover it up. Letting out a small 'eep', he shot up from his chair, grabbed all his stuff and ran out the door. He ignored the startled yelps around him and even the voice of his professor as he scrambled out, dashing through the campus as quickly as possible. He ignored the odd looks he received considering how fast he was moving, but he was willing to accept the strangeness than have them find out the truth.

He needed to get home. He needed to get home right now before anything else started popping up that couldn't be well-hidden under his clothes and his backpack. If he didn't make it in time then he would have to find a place to hide until night where he could use the darkness to shade his extra features. Tsuna didn't want that though and would rather avoid such an extreme, thinking of using it as a last resort.

As he ran down the familiar route to the train station and dodging anyone that got in his way, his mind was so completely focused on getting out of the area that he didn't notice a dark individual step before him from around the corner. Luckily with his superior speed, he was able to dodge the man just before they crashed and jumped back to the side to keep going. He huffed, peering up to stare at the man that had gotten in his way, ready to apologize and move on.

Except when his eyes connected with those onyx ones, he froze into his spot and felt like all the air in his lungs was forcefully sucked out.

He blinked and quickly examined the individual before him, his instincts catching that the other was feeling the exact same way as him, those alluring dark eyes widening in surprise. Tsuna didn't say anything, simply observing the taller man whose spiky black hair appeared in shades of the nightly darkness. The man's hair, however, was covered up by a black fedora with a yellow band wrapped around the bottom interior and had two sideburns that were curled perfectly against his face.

"So...Umm..." Tsuna muttered uneasily, unsure of what exactly to do. What was he supposed to do? He wanted nothing more than to head home to take his medicine. However, his body refused to move, refused to do anything other than stand there and stare.

The man, Reborn, was the first one to recover, snapping out of whatever trance he had fallen into, and took a single step back to observe the situation. He hummed gently, eyes narrowed as they roamed over Tsuna's body before finally locating something that had caused the whole issue.

"You're a werewolf." Reborn stated as if talking about the weather, onyx eyes gazing directly at the extra set of ears. He took a small sniff of the air and automatically licked his lips as a pleasant scent entered his nostrils. His eyes dilated as something... strange flushed through his body and it only got worse as he continued staring. It was like every cell of his body was alive, bursting with a sudden energy he couldn't quite explain. As he observed the brunet, it was obvious the other was feeling the exact same way.

Lust, complete and utter lust. Their blood was boiling uncontrollably, demanding each other to claim one another. Tsuna took a step back, his body shaking as he tried to fight off... whatever was trying to control him. His eyes glowed orange and he tried to contain his breathing from actually inhaling in the man's delightful scent. Reborn swallowed audibly before reaching forward, grasping the smaller male's shoulders, and dragged them both off to an abandoned alleyway. They didn't need any curious eyes watching them, it was the last thing they needed considering their newfound situation.

However, the second they were out of sight, Reborn shoved Tsuna against the wall, forcing each other to face the opposite. The raven loomed over the brunet, taller in size by at least a head's length, and smirked lustfully. Tsuna pressed against the wall, wanting nothing more than to than blend into it and disappear. However, every nerve in his body was telling him to surrender and to either just claim the man before him or let himself be claimed instead. Reborn huffed, "What's your name?"

"T-Tsuna..." The brunet felt his cheeks unwillingly heat up at the husky timbre tone, attempting and failing to squash down his desire. "Yours?"

"Reborn."

"A-Ah..." Tsuna glanced to the side, trying to turn his attention elsewhere, but every part of his body was demanding to look back. Eventually, he did. "Are you also a-"

"Werewolf? Obviously, yes." The raven leaned forward, just enough to where Tsuna could feel the warm breath tickling against his cheeks. "I'm afraid we're connected."

Tsuna blinked questionably. "Connected?"

"Apparently, we're mates, given by the way our bodies are reacting to each other."

"Hieee!" The brunet mentally cursed. He had hoped he had gotten rid of that irritating screech of his. However, he didn't belittle himself for it, finding the situation utterly deserving. Still, he didn't deny it, his body and instincts telling him that it was the definite truth. He let out a small curse, unable to believe his horrible luck.

Reborn snorted, flickering his fedora upward to reveal more of his face. "I don't like it either. I don't like anything attempting to control me." His onyx eyes glowed yellow and Tsuna swallowed at both how handsome and dark the man appeared. "But..." His eyes raked over the brunet's body once more, licking his lips amusingly. "I'll make this exception just once. At least fate gave me a cute one."

Without saying anything or even allowing the brunet to reply, the raven shifted forward, pressing his body against the other. Tsuna let out a small 'eep,' but didn't resist, his instincts keeping him from actually responding negatively. He peered up in wonder, lips slightly parted, and simply watched. He didn't do anything else but stand there, ready for whatever was to come.

Taking that as an invitation, the raven leaned forward for a kiss, starting off slow and subtle to test the grounds. The lips he touched against were soft and gentle and it was that single touch that was needed to set him off. Immediately, everything changed and Reborn simply felt utter hunger, the yearning to claim, to take the brunet entirely right then and there. That very same sensation washed over Tsuna's mind at the same time, the brunet reaching up to grasp Reborn's yellow button-up shirt.

Without wasting another second, the older male thrusted his tongue inside the cavity, pushing through the parted lips, and dominating the kiss with ease. He listened to the short moan as Tsuna groaned against the kiss and then again as he pushed his body harder against the brunet's, crushing him against the brick wall. His hands wandered, cupping below Tsuna's ass and raising him up so the other could easily wrap his legs around his waist, giving him perfect leverage to grind their groins together heatedly. As he did so, he listened in delight as the college student groaned loudly in bliss, breaking the kiss. Reborn's hands went back to wandering, his left heading up to thread through those spiky brown locks while Tsuna quickly wrapped his own around the taller man's neck, attempting to keep himself steady. Meanwhile, the raven grasped a couple locks and tugged Tsuna's head to the side, revealing pale neck skin, just demanding his lips to run against. He was never good at denying his desires.

Smirking, he leaned over and buried his face against the crook of the neck, brushing his lips against the soft flesh. He could feel Tsuna shivering under his touches, eyes closed tightly shut, and gasping lightly whenever he went over a particular sensitive spot. Finding one, he bit down, not enough to draw blood but did leave a mark, a mark that clearly stated that the brunet was his and his only. Werewolves were territorial creatures after all and didn't like it when someone overstepped into their boundaries. Their reactions towards that offense were quite...violent.

Releasing his grip on the hair, he went back to threading his hand through the soft tresses until he found the right ear. It twitched against his touch before he grasped the insides, massaging the highly sensitive interior. He was rewarded with a loud mewling and the tightening of the legs and arms around his body, Tsuna's orange-colored eyes wide open.

Combined with Reborn's kisses along the neck, the grinding of their hips, and the rubbing of the ear, Tsuna was in absolute pleasure. All thoughts had been thrown out of his mind, drowning in sensations he hadn't experienced before, and could do nothing but accept his fate. It helped that everything felt so deliciously good and oh so right. Every nerve in his body was on fire, desiring exactly what this werewolf was doing to him and more. Each touch, each kiss, each push, just sent sparks up and down his body before finally pooling in his abdomen. His groin was pulsating painfully, demanding release, and he could tell Reborn was just as hard as he was.

Reborn growled deeply, pulling back so he could gaze into those orange-colored eyes, his own tinted bright yellow. "Mine."

Tsuna could tell the territorial part was taking over and in turn, dragging his own out. It was purely instinct, genuine uncontrolled instinct, that wanted to take complete dominance over his actions and by the looks of it, Reborn's too.

"Mine." Reborn went for another kiss, all hot and wet, dragging out another loud moan from the back of Tsuna's throat. It was only then that he pulled back, eyes glancing around. Sneering, he released the brunet, still holding him up just enough to get his baring before yanking the college student beside him. "Come, we're finishing this at my place."

"Your...place?" Clearly the pleasure was slowing his mental processing of the conversation, his body clearly upset by the lack of heat.

Reborn smirked, "Ah, yes. My place."

Tsuna blinked once, twice, before finally nodding, allowing himself to be dragged down the alleyway to Reborn's apartment with his book bag in one hand. He had already decided that whatever happened to him would be fully blamed on his werewolf's commanding instincts that still haven't shut up. Licking his lips, still able to taste Reborn, he pulled himself a little closer to the raven and smiled.

Hope you enjoyed it (both the readers and the tumblr asker). Don't forget to leave reviews on your way out :)