Here goes everything...


Rin and Yukio exchanged glances, not sure if they heard right.

"Could you kindly repeat what you just said, Mr. Pheles?" Yukio asked, a look of disbelief on his face. Mephisto smirked at the brothers, who sat stiffly on the big purple couch opposite him.

"What's with your reactions? I've been in a Christmas mood lately, so I thought, why not grant my two favorite students their birthday wishes? It makes sense, too. Your birthdays are close to Christmas, right?" Mephisto said, as though him giving out free gifts was a very normal thing. Which it wasn't.

But despite the suspiciousness of it all, Rin was never one to turn down a free gift; especially if it was going to be something that he wanted really badly. So he readily accepted the Headmaster's offer, grinning as he practically skipped out the doors of the office. Yukio, on the other hand, stayed behind and glanced at the demon, who stared back at him from behind his (expensive) cherry mahogany table.

"What are you planning, Sir?" Yukio asked. Mephisto pretended to look hurt.

"Are you doubting me, your wonderfully generous Headmaster?" He said dramatically, but then burst into a sly grin. "Worry not, Okumura-sensei. All I wish for is to grant wishes this Christmas. It is also a very special year, after all." Yukio merely narrowed his eyes in suspicion and bowed before leaving the office.

As the door closed behind Yukio, Mephisto smirked, undoing his illusion. He stroked the Leaper, which had been settled comfortably on his table all this while, and using his own demonic telepathy to look into the Leaper's mind, he grinned. "Well, my dear brothers, let us see what your hearts desire…"

Christmas swung by quickly, approximately a week after Mephisto had called his half-brothers to his office. Yukio was still wary of the purple-haired demon and his promised birthday presents, but Rin had been looking forward to his gift ever since then. That was why, after the Christmas/birthday party held at the old boy's dorms, Rin followed Mephisto to his office eagerly to collect his and Yukio's gifts while Yukio stayed behind to clean up with the other cram school students.

Once the cleaning up was done, and the crowd gone, Yukio went back to his room and flopped onto the bed. He glanced over at the clock on his bedside drawer, tensing and jumping out of bed when he saw the time.

"It's already this late? Where's Rin?" He asked aloud, but no one except a drunk, out-cold Kuro was there to hear him. His blood started to boil when he thought of Mephisto. "He'd better not be doing anything weird to Nii-san…" He trailed off, clamping his mouth shut and shaking his head to clear any indecent thoughts. He then decided to wait slightly longer, and then storm into Mephisto's office later if Rin didn't come back anytime soon.

Of course, he wasn't expecting what happened next.

A loud thump against the door was followed by a muffled voice which he recognized to be Rin's. Relieved but concerned, Yukio darted over to the door and opened it, only to have his brother's limp body fall onto him.

"Nii-san? Hey, get a hold of yourself!" Yukio lifted Rin off him, and laid his older brother on the floor. He was panting heavily, his eyes squeezed shut and his face flushed. "Are you okay? What happened?" Yukio asked, worry evident in his voice, but when he touched Rin's forehead, the latter jerked away, whimpered and let out a very erotic moan. Yukio's eyes widened and he quickly pulled his hand back, a blush starting to form on his face. "Nii… san…?"

"Ngh… Yu… Yukio…" Rin groaned, an eye cracking open to look up at his younger brother, who just looked at him with a concerned face.

"What on earth happened, Rin?" Yukio asked, not sure if he should bring Rin over to his bed. He was a Doctor, but he doubted that he could control himself if Rin made any lewd noises. It was Rin, after all… Said boy merely writhed on the floor, trying to curl up on his side but cringing as though every small movement was hurting him in some way. "Rin!"

"Stupid… clown… He said… it was… candy…" he murmured breathily. Yukio frowned, and decided to help Rin to his bed before checking if he had anything to counter whatever drug Mephisto had given his brother. He slung Rin's arm over his shoulder and dragged him over to the bed, trying his hardest to stay professional and ignore the temptation of jumping the other boy.

Setting Rin down onto the bed slowly, he decided to leave the checking of symptoms for later and prepare the medicinal kit, hoping that by stalling for time he would be able to calm his raging hormones. Rin whimpered loudly, and Yukio turned around in time to see Rin weakly trying to pry his clothes off his body. "Hot… It's so hot… Yukio…"

"It could be a fever… Nii-san, hang in there. I'm gonna go get some water to sponge you down," he replied, grabbing a towel and running out of the room, into the empty hallways, away from a very, very erotic Rin…

'Snap out of it, Okumura Yukio!' he thought as he ran to the sinks, mentally kicking himself for thinking about his brother that way. Sure, he'd always had much admiration for his brother, and it was true that there was a time when he might have developed a tiny crush on him…

'That was years ago. You're 18 now, Yukio, you should know how to keep your cool and act like a proper 18-year-old.' He grabbed a small basin from next to the tap, and filled it with cold water. 'It's about time to leave behind those childish feelings and face reality. You're brothers, you're both men…' Yukio turned off the tap and, throwing the towel into the cold water, made his way back to his room as quickly as possible without spilling any water. 'It's the ultimate sin. Not to mention, we're both already legal adults…' That last thought did not end as expected for Yukio, and he dipped a hand in the cold water and splashed it on his face to clear his thoughts.

"Nii-san, I'm back," Yukio kicked the half-open door, entering the room and glancing over at Rin, who'd already stripped himself of his shirt. Yukio swallowed and worked quickly, setting down the basin and wringing the towel of excess water. He turned back to his brother and was ready to help sponge him down, but he did not expect a whining Rin to slip onto his lap and wrap his arms around his neck. "N-Rin…?"

"Yukio, please… help me out…" Rin panted, burying his face into his shoulder and weakly grasping Yukio's shirt. The younger's arms hung limp at his side, and he wondered if he should wrap them around Rin, who had pressed his body against Yukio's. The latter felt something hard brush against his thigh and blushed, flinching slightly, his thigh jerking upwards and the friction causing Rin to moan loudly.

"Nii-san…" Yukio gulped, and leaned away from his older brother, whose facial expression was making it hard for him to say no. 'Just this once… ' The bespectacled teen finally succumbed to his desires, and hesitantly placed his lips on Rin's. He was answered with a hungry growl as Rin responded fiercely, already biting on Yukio's lip. The younger twin smirked and opened his mouth, only to force his tongue into his older brother's. He wasn't going to be easily dominated.

Rin didn't care much about dominance, though, and it seemed as though all he wanted was more; more kissing, more touching, more of that delicious friction against his groin… Yukio didn't mind it at all, and soon found himself sporting a matching erection. "Yukio…" Rin's voice was muffled against his twin's lips, which had now moved down to his neck and was leaving a wet trail of bites and kisses.

"Hold on, Nii-san," Yukio exhaled, and lifted Rin up so that he could move the both of them over to the bed. He removed his glasses, pushed Rin down onto the mattress, and his older brother watched with lustful, half lidded eyes as he stripped himself of his own yellow T-shirt.

"Yukio…" the half-demon moaned as his twin went back to attacking his collar bone, his back arching off the bed when Yukio bit down on a particularly sensitive spot. Yukio smirked against Rin's flushed, sweaty skin and nibbled on that spot, sucking slightly. He pulled away to see a lovely red mark.

"You're mine, Nii-san…" Yukio breathed, and went on to undo his brother's pants, as well as his own. Seeing a mewling Rin in only his boxers with an obvious tent in front was sinfully erotic, and Yukio tore at them, unable to control his lust. Rin gasped as the cool air met his warm skin, back arching off the bed once more as Yukio's hands roamed over every inch of his now exposed body.

"Agh, God… Yuki-!" Rin cried as a hand wrapped around his painfully erect manhood. Yukio could only smirk.

"You're already so wet, Nii-san…" He rubbed a thumb over the tip of Rin's member, and finding his reactions and whimpers extremely addictive, immediately set to work on eliciting more of those sounds and actions from his older brother. Yukio slid down Rin's body so that he faced his erection, and tentatively took it into his mouth. Engulfed by the hot, wet cavern that was Yukio's mouth, Rin couldn't help the long, loud moan that escaped from him.

"Nn, Yukio!" He panted, as Yukio slid his tongue over and around the head of Rin's penis. He then started to lick along its length, stroking it as the elder came into his mouth with a groan. Yukio used his hand to wipe away some of the cum that had landed on his face, and then proceeded to kiss his older brother, who shuddered when he tasted his own seed on the other's tongue.

"Had enough, Rin?" He asked as he pulled away. The other boy growled, pulling him back.

"Hell if I did," he replied, and their mouths smashed together once more. Yukio noticed that Rin was still hard, but his suspicion quickly melted away when the latter ground his hips against him.

"Ah!" Rin yelped when Yukio pushed him down onto the bed once more. When Yukio placed his fingers on his mouth, he gave him a confused look.

"Lick them," Yukio commanded as he removed himself of his own boxers. "I don't want to hurt you too much…" Rin obeyed, and used his saliva to coat Yukio's fingers as thoroughly as possible. Once he thought they were wet enough, Yukio took them out from Rin's mouth and moved them downwards. "Should I continue? There's no turning back after this," he whispered into his brother's ear. Rin just wrapped his arms around Yukio's neck.

"Just hurry up and do it," he panted. Yukio used a finger to circle Rin's hole, lubricating it, and then slid the finger in. Rin squeaked, the intrusion feeling very foreign to him. Yukio paused, afraid that he was causing him pain, but a squeeze on his shoulder from Rin urged him to continue. "It's fine, so… please…"

Yukio nodded, and wiggled his finger around. When he added another finger and started scissoring, Rin couldn't help but cry out in pain. Yukio tried to comfort him by whispering encouraging words into his ear and trying to get him to relax, and once he felt Rin was ready he added a third finger. "Nngh, ah!" Rin cried, but as Yukio's fingers probed inside him, he found himself getting used to it.

"Is it okay now?" Yukio asked, stroking his brother's hair. Rin looked up at him and nodded. Withdrawing his fingers, Yukio positioned himself at Rin's entrance, and slowly pushed himself in. Rin squawked, clutching at the sheets. His cries were silenced when his twin captured his lips, and Rin groaned into Yukio's mouth when the other was fully sheathed in him.

Yukio started a slow pace, and once Rin adjusted he started to go faster, with the other eager to meet his thrusts. The both of them were panting heavily now, Rin emitting the occasional moan while Yukio grunted with each thrust. When the latter changed his angle and rammed upward, brushing against Rin's sweet spot, Rin responded with a strangled moan, louder than those he had been producing until now. Yukio smirked, aiming for that spot with every subsequent thrust, and all Rin could do was gasp and moan, face flushed, eyes squeezed shut in pleasure.

"I'm… close…" The half-demon wailed as he fisted the sheets. Yukio gave a few more hard thrusts and came inside his brother, who followed soon after. Rin's seed splattered over this chest as he arched off the bed, his moans dying on his lips. Yukio smiled and pulled out, flopping onto the other as they continued their heavy breathing.

"Suki da yo, Yukio…" Rin murmured, his eyes closing as he drifted off to sleep. Yukio's eyes widened in surprise, before he smiled in content, pulling his brother into a warm embrace.

"Me too, Nii-san… Happy birthday."

Mephisto's eyes gleamed as he set his binoculars down and sipped at his tea. He glanced at the bag of candy that Rin had emptied, and giggled madly as he took out an empty bottle of aphrodisiac pills.

"I hope the both of them enjoyed their presents!"

Yes, I know it's not their birthday(s) yet. But this was bugging me, so I just had to.

This was my first time writing a lemon, and I won't deny, I was grinning like an idiot while I wrote it... Comments and tips to improve will be greatly appreciated.