Yay! My first crossover! I like it even though its short 'cuz it's all fluff and cutesy stuff! To any of you who are wondering how I came up with this, blame the AMVs. I just thought that Sting would be very clingy and submissive to make up for his aggressive and brash personality.
Whatever! Let's get on with the story! Enjoy!

Warning: Sting and Yukio may appear to be OOC. If there is a need to criticize on my writing, try not to make it too offensive.

~StiKio~

The blond demon scowled as the young brunette teacher passed by him without even glancing his way. Sting knew that they had recently broken up but the way Yukio acted greatly displeased the elder. The teacher acted like they were just acquaintances. The nerve! The demon knew that he was the one who broke up with the other just because of sheer jealousy. Rin seriously acted too clingy towards his younger twin. He did not like it when someone tries to touch what belongs to him, even if Rin was Yukio's brother. This trait, after all, belonged to all submissive demons, such as Sting Eucliffe himself.

However, when the half-demon heard of Sting and Yukio's separation, he quickly made his way to Sting to apologise. Rin explained about how he found the lack of attention from Yukio to be quite upsetting since the two had always been inseparable. The raven head had absolutely no intention to make the older demon jealous of him. Sting could hear the sincerity behind the younger's words, so he accepted the apology without a moment's hesitation.

How did Sting Eucliffe and Yukio Okumura meet? Simple, Yukio simply tended to the wounds Sting's friend, Rouge, had, only due to the fact that the great wound could not heal properly. If it was not treated, Rouge could go berserk from the immense amount of pain he constantly felt on his tail. Since the tail was the most sensitive part that belonged to a demon, the whole situation was understandable.

Sting felt very grateful towards Yukio 'kindness', despite already knowing that it was just 'orders'. The demon lived by a rule he made for himself; When one helps you greatly, you have to shove everything else aside and do whatever it took to repay the debt. Sting literally followed Yukio everywhere, meaning also during his regular school time – Sting was a demon so most of the students cannot see him – and while he was teaching in Exorcist Cram School. However, Sting's loyalty grew to something like fondness, and then it evolved into so much more. Yukio, on the other hand, found Sting's presence to be something very fortunate for him to have. It prevented him from feeling lonely on some occasions and the teacher found himself quite disappointed when the blond demon was not near, even if it was just for a moment. Of course, rumours of Sting being Yukio's loyal 'boyfriend', and so on, arose. Soon enough, those rumours became facts, except the dirtier ones.

That all leads to the current situation at hand.

Sting dragged his feet to the kitchen that resided in his and the Okumuras' dorm. He sat on one of the seats and slammed his head on the table, not caring to lift it up while ignoring the throbbing pain in his forehead. Due to this, he failed to realise the demon cook sliding a cup of hot chocolate in front of him. Yes, it was winter at the moment. Ukobach hummed in order to gain the blond demon's attention. Sting slowly lifted his head from the table, which now had a dent in it, and finally noticed the small demon giving him a worried look.

"Thanks Ukobach," he thanked, a sad smile set on his face as he brought the hot beverage to his lips. Oh, how his big brother Natsu would love to drink this now.

Sting let out a contented sigh at tasting the blissful chocolate drink. He thanked the small demon, satisfying Ukobach.

"It's the 26th of December," Ukobach stated, speaking in the Gehannan tongue.

At hearing that, the blond's demon tail shot up and he stopped sipping on the drink in an instant.

"I... haven't thought of a present... or how to apologise to 'Kio-kun," Sting told the demon, looking down at the contents of his drink.

"I might have a solution to that," Ukobach whispered to him, a cheerful smile set on its face.

After some whispering...

"He'd never be so desperate as to forgive me so easily."

When Yukio woke up, he thought that he might find a certain demon curled up next to him. To his dismay, the bed only remained half-empty. It was Yukio's birthday and he knew he should enjoy it but how can he? The demon he proudly declares as his boyfriend proudly was nowhere to be seen. There was absolutely no way, Yukio could enjoy the 27th of December without his other half.

The brunette sat up and rubbed his eyes. When his vision became somewhat clearer, he was greeted by the sight of Sting sitting by his bedside and holding two mugs, on in each hand. Well, so much for Sting being nowhere to be seen.

"Happy Birthday Yukio," the blond demon greeted, handing one of the mugs to the teen.

Yukio slowly reached out to grab the mug's handle, careful as to not burn his hands since it was filled with hot chocolate.

"So..." Sting began awkwardly, "About us never getting back together..." the older fidgeted, taking a sip from his own hot chocolate in an attempt to calm his nerves.

This was it. Yukio's heartbeat quickened, hoping that they would indeed get back together. He felt like he was dying inside every time he barely spared a glance at the blond.

"I didn't mean-"

Yukio did not have to wait for Sting to finish his answer. The brunette interrupted the elder's sentence, crashing his soft lips onto the demon's own. Sting's eyes widened in surprise at the sudden reaction from Yukio. Ukobach's advice worked too well that it was easier than a piece of cake.

The kiss was brief though but the blond was too surprised to even notice. Yukio noticed this and chuckled, licking his lips and savouring the taste of hot chocolate from Sting's mouth.

"Apology accepted Sting. By the way, that was some good hot chocolate," the brunette said, dragging the word "good" to emphasise his point.

"You were just as depressed as me huh..." Sting stated bluntly.

"Why wouldn't I? You clearly stated that, and I quote; "We are never ever ever getting back together"."

"Well, I'm pretty good at lying."

OMAKE

"Okay class, can anyone summa-"

"'Kio-kun!~"

Yukio was rudely, but affectionately, interrupted from his teaching when a very pouty blond tackled him to the ground. The Exwires' eyes widened at the scene, silently praying for the demon to make it out safely.

"You weren't with me when I woke up!" Sting whined, looking at the teacher with teary eyes.

"It's that time of the month," a certain pinkette mumbled to himself. This earned him a growl from the moody demon as he had sharp hearing.

"I had an urgent meeting Sting," Yukio told the elder, attempting to gently pry the blond off of him.

"At least leave a note!" Sting exclaimed, nibbling on the young Exorcist's earlobe.

Yukio let out a sigh, standing up with Sting. Actually, what Shima had said was true, since the blond demon was a submissive one. The brunette definitely could not teach his class if the whiny demon did not calm down. Once again, the young teacher sighed and settled to ease Sting's whining fest by using a few simple words. Yukio leaned towards Sting, his breath brushing the demon's ear, whispering, "If you stay good, I'll reward you when we get back."

Heat rushed to Sting's face when he heard Yukio's husky voice. He could tell that the teacher was smirking.

"Hey four-eyes," a certain half-demon with sharp hearing called, "stop flirting already."

Yukio chuckled in response but did exactly what his older twin told him to do. Sting, as usual, took a seat behind Rin.

"Alright class, putting that small distraction aside, can anyone summarise yesterday's lesson on A Demon's Habits Towards Their Mate?"

At hearing that, Sting banged his head onto the study desk for the umpteenth time that week, muttering the word 'smartass', 'meaning' and so on before paying attention to Yukio.

Thank you for reading!