A/N: I'm kind of crazy. Can you tell? I think this will remain a PWP one-shot for now; testing the waters to see what readers are interested in, ha ha. For those of you who are not familiar with Katekyo Hitman Reborn, the "Ten Year Bazooka" mentioned here will be explained in the story, so don't worry. Reviews are greatly appreciated! Thanks and enjoy.

Word Count: 2,149

Warnings: Glorious debauchery of the slash nature.

Summary: Oga and Baby Be'el accidentally use the Ten Year Bazooka to summon a twenty-one year old Beelzebub IV from the future, who has shocking news for his adoptive father. Beelzebub IV x Oga Tatsumi, slash content, dub-con one-shot.

"You Taught Me"

"What the hell is this, Hilda?" Oga stared at the bazooka-like object with disdain. He had learned very quickly that nothing from Hell was safe – not the demons, not the babies, and especially not the children's toys.

"The Ten Year Bazooka," Hilda answered. She was balancing another load of boxes from Hell, "It switches the current target with their selves ten years in the future."

Oga blinked, "What? Well, that's useless."

"You don't know that."

The delinquent shrugged, "It doesn't do anything cool, like a real bazooka should." He flopped down onto the bed and watched Be'el as he played with some blocks. Hilda dropped the load of boxes off by the desk.

"I have to make another trip to Hell, it might take a while," she said, rubbing her shoulders. She started out the door again, "There are more where these came from. And do not touch anything in here until I come back, understand?"

Oga nodded in her direction, but other than that, he showed no signs that he heard her. He had plenty of other things to worry about, like Be'el, who was now visibly bored with the blocks. Of course, the baby cried less often now, but Oga could never be sure about what ticked him off. "Baby Be'el!" he called.

Be'el looked at him inquisitively, "Da?"

"What do you feel like doing?" Oga tried, getting up from the bed to sit next him. Be'el looked around slowly several times before his gaze finally landed on the Ten Year Bazooka.

"Da!"

"That? Isn't that…" he looked at it, "The bazooka thing? I forgot what it did. Something about years, right? Maybe I should ask Hilda again, wait here." Oga peered down the stairs when a sudden crack alerted him to the smoke. "Baby Be'el!"

He was taken aback when the figure of a small child came tumbling out of the haze; he looked about eleven or twelve, clothed in a t-shirt and some jeans. If this was the same Be'el he knew, his nose was no indication. The yellow ball which Oga had thought was a pacifier at first was gone, replaced by a completely normal nose. His hair, Oga realized as it quickly dawned on him, was a distinct shade of mint green, "… Baby Be'el?"

The child looked up at him, teary eyed, "Dad?"

Silence.

No, no, no. Oga shrunk back. It was too soon to hear Be'el speak. Way too creepy. With a rush, he scooped up the Ten Year Bazooka. If he shot Baby Be'el again, that would undo the effects, right? Right? It must be an on-off sort of thing! Without really thinking it through, he aimed it at the Child Be'el and pulled the trigger. Another wall of smoke obscured his vision; he squinted apprehensively into it, his eyes searching for the familiar baby, but what walked out of the haze was not a baby. It wasn't even a child. Oga swallowed the forming lump in his throat as he looked, finally, upon what seemed to be Adult Be'el. Crap, Hilda was going to murder him.

"Baby Be'el?" Oga asked, "Is that - well, I can't call you Baby Be'el anymore… Be'el, is that you?"

"Kaiser de Emperana Beelzebub IV to you," the man replied coldly. He was taller than Oga now, slender and pale, and Oga had no doubts a lithe figure was shrouded under the cloak. The same piercing green eyes and green hair greeted him as the smoke finally cleared. Adult Be'el stared at him for a while, and then he finally spoke, "Oga Tatsumi… long time no see."

His eyes immediately lit up at the words, "So you finally found someone stronger than me, huh?" That was great! He knew now that in at least twenty years' time, Baby Be'el would be off with someone else. "So who was it? Toujou, I'm sure. Or maybe even Miki or that Rokkisei bastard, Izuma?" He stroked his chin thoughtfully.

The Demon King's face darkened, his fists clenched at his sides, "No. I didn't find someone stronger." In fact, he thought, he hadn't found someone stronger since Oga… he turned away from his adoptive father.

"Then Hilda took you back to Hell, right? That's good! Your real father should be raising you," Oga grinned approvingly.

"No, she did not," Be'el said thickly, "You were my only father."

"I don't get it, if you hadn't seen me in a long time and you're twenty or something, doesn't that –"

"You died!" Be'el snarled suddenly, whirling around to look Oga in the eyes, "You died, alright? A long time ago… I haven't seen you since I was…" Oga stared at the man in front of him as though he had grown two heads. "And Hilda, she's gone too."

The delinquent stilled. He sighed and finally reached out to give Adult Be'el a shaky pat on the back, "At least you didn't cry, right?"

"No," Be'el said plainly. He grasped Oga's wrist, pulling the younger man into a tight embrace, their bodies held flushed together, "It's your fault I was alone, Oga. If you hadn't died, I wouldn't have become this way," he murmured accusingly, though it was merely a statement. Oga stiffened in his arms; he didn't know if he was frozen out of confusion or fear, but it was all the same. Even if he could move, he wouldn't know what to do. Hug Be'el? Shove him away?

Oga glanced up at his face, his eyes were partially covered by his green hair, but the tell-tale sign were his lips, which were pressed into a thin line. He looked hurt… because of Oga? "Er," he started lamely, "I… you're really different from when you were a baby." Argh, he was never good at this comforting thing. Be'el stared at him blankly. It bothered Oga, the limp hug, the dead eyes – something was wrong, terribly wrong. It roiled something in him. What was this indifference in his face? Oga died; shouldn't Be'el be angry at the most and indifferent at the least? But here he was, a full-grown man was stewing in his own self-pity: the same man who should be the Demon King. Then it hit him: Be'el had given up. The listlessness wasn't sorrow or heartache... it was resignation. Without word or notice, his fist had connected with the Demon King's face, and the man staggered back, his eyes wide in disbelief, and the corners of his lips twitched as though he wanted to say something.

"Coward!" Oga roared, "I didn't teach you to mope around and give up, you bastard! So what if I died? It must have been spectacular! Like I duked it out with my arch-nemesis and we both died at the same time or something! Don't sully my memory with your sniveling, Be'el!" Oga glared at Be'el, who still seemed to be frozen in shock.

"Don't call me a coward," the demon eventually responded, straightening, "You don't know anything about me."

"Coward."

"Don't test me," Be'el warned.

"You," Oga pointed directly at him, "are a big, stinkin' coward." In a blur of motion, Be'el had his fist lodged in the deliquent's stomach. Oga sank to his knees, coughing violently, but his lips curled into a mocking smile, "Is that all you've got?"

Be'el slammed him into the floor by his throat, almost rendering Oga unconscious; his head lolled slightly to the side… the pain in his head was so sharp that it had him seeing red. It was a sure fact that if he hadn't grabbed the hand before it closed around his throat, he would no doubt be feeling the full effect of Be'el's strength – that is, a crushed neck. He could barely see straight, much less fight back now. Be'el loomed over him, "You also taught me to take what I want." He grabbed Oga through his shorts, eliciting a startled yelp from the delinquent.

"Be'el, stop! This isn't what I meant!"

The demon stopped, "What do you mean? Isn't this what you said? Take what I want?"

Oga tried unsuccessfully to pry the steel grip away from his neck, "This… this isn't what you want!"

Be'el leaned over, legs on either side of Oga's thighs, and nibbled sharply at his collarbone. "I know exactly what I want," he said evenly, "You."

"Not like this," Oga wheezed. Be'el ignored the struggling and merely tugged the shorts off, throwing them into a pile by the side of the bed. In silence, and except for the sound of Oga futilely trying to free himself, Be'el shoved the thin t-shirt up to reveal a wide expanse of toned, milky skin. It was marred by scars and some fading bruises, but breathtaking to run his fingertips over. It was as warm as he thought he would be. Be'el let his hands ghost over Oga's thighs, his hips, his waist – his hands explored places he thought he would never be able to; at least not anymore. He raised a tentative hand to his mouth, trembling as he sucked his own fingers.

"Oga," he rasped. He both hated and loved the man. Hated him for planting a deep-seated weakness, hated him for being weak himself even though he carried the burdens of others; loved him because he cared in his own twisted way, loved him because he could convey his feelings without ever having to say a word. "Oga, just once – today," Be'el pleaded.

"No… Be'el," he said desperately, "I said you should take what you want… but this isn't how you –" The demon flipped Oga over soundlessly, smashing his face into the floor again. Be'el growled, trailing a hand over his ass gently before prodding the puckered flesh there with a saliva slicked finger.

"Stop! Be'el!" Oga's voice raised an octave, his mind stricken with panic, "Be'el!"

If there had been any pretense of tenderness or kindness earlier, it was completely stripped away now. Oga's pleading struck a dark chord in his chest. Without warning, he forced all three wet fingers in, wrenching a whimper from the figure beneath him.

Oga gasped and choked back a growl, but he nonetheless was silent now. He would let Be'el have this – it was his fault, after all, that Be'el was alone and was hurting. He should have been strong enough to protect his charge; this burden was wholly his. If anyone knew the price of failing to carry a burden, it would be Oga. And damn, he cursed, this was a steep price to pay.

Be'el continued to pound into the complacent Oga. The slick sound of flesh meeting flesh was the only sound in the room until a sudden jolt of pleasure seized him. He scrambled for purchase on the wood floor, groaning loudly - to Oga's credit, the first real lewd sound. The Demon King grinned, leaning down to lick a stripe down his neck, "How does that feel? I found it, didn't I?"

He received a garbled reply from the quivering delinquent. Satisfied, Be'el began thrusting in earnest, sliding out all the way before slamming back in. Oga whined every time he was fully sheathed. His cock was so hard he thought it might shatter, yet that pale hand at the base prevented him from doing so. He could feel tears of frustration welling up, and his body hummed with a kind of arousal he had never felt before.

"I thought you said real men didn't cry," Be'el noticed and smiled icily, "You taught me that." He spread Oga's legs with his knees so he could slide in even deeper, wringing a throaty growl from Oga.

"This," he gasped, "isn't what I meant!"

"Isn't it? You taught me everything I know now. Recklessness, cruelty, mercilessness – all from you," he punctuated each word by driving in deeper, "Isn't this just a culmination of all your teachings, father?" Oga was so high-strung with lust at this point that he could have snapped. The Demon King continued casually, as though he wasn't fucking his younger adoptive father, "I succeeded the throne with no threat from my brother, thanks to you. En was… well, he had the ambition, but he lacked the attitude."

Oga could barely hear Be'el over the sound of his own wildly beating heart. Something came apart in his mind as the pleasure reached its apex. "Be'el," he cried hoarsely, "Please!"

Be'el smiled and wordlessly began stroking Oga's weeping erection; it didn't take long for Oga to come with a jerk into his hand, groaning loudly. The Demon King thrust into the warm body a few more times before he came with a shudder too. Oga and Be'el lay panting on the floor for a few minutes, slick with sweat and come.

"Don't leave me this time," Be'el murmured into Oga's neck.

Oga nodded sleepily, "I promise. And I said real men don't break promises, right?"