A certain adult Reborn studied the new bullet that came out of Leon, shrugged, and fired at Tsuna.

At first, nothing had changed. But then the rush that went to his head and...down?

He lay still for a moment, so still that Reborn actually became worried. Until he sat up again, and said, "Reborn, what-"

And then he ran away. And came zooming straight back. Reborn watched with interest. Tsuna halted in front of him, then said breathlessly, "help," before falling and wrapping his arms around his neck.

Reborn froze. "The fuck?"

Tsuna didn't move, still trembling. Reborn, very, very uncomfortable, prodded his side with the barrel of his gun. "Dame-Tsuna, let go."

Tsuna only gripped him tighter, then nuzzled his neck.

Reborn gripped Tsuna by the shoulders, then shoved him aside, so violently that he flew against the wall with a sickening crack. Tsuna stood, unfeeling of the pain, as Reborn pointed the gun at him. "Dame-Tsuna, control yourself."

Tsuna looked him in the eye and the raw lust that lurked there whacked Reborn over the face violently. "I can't," he pleaded, lunging forwards again. Reborn skipped neatly aside.

"I don't like children," he said with distaste. "Especially not after having spent years as a baby. I certainly don't want anything to do with you-"

Tsuna managed to wrap his arms around Reborn's neck again, and Reborn sighed. "Oh, fine, have it your way."

Reborn, still standing, shifted Tsuna until he was piggy-backing him. "But we are not doing anything outside of this."

Tsuna's only movement was the trembling. "Damn," he mumbled, gritting his teeth. "Reborn, that bullet-"

"Is probably causing the victim to be near the perpetrator," he mused.

Tsuna stiffened. "Y-Yeah."

Reborn perked up. "What is it?"

"Nothing."

Reborn paused, then punched his leg, unable to get to his head easily. "Dame-Tsuna."

Tsuna gave his signature cry, flinching. He still didn't let go. Then he tightened his grip, smothering Reborn.

"You're hiding something."

"I-I-"

"Is it that you were already attracted to me?"

Tsuna didn't reply, and Reborn sensed the answer was a resounding yes. "What terrible timing. I'm your tutor. Not to mention, I'm not inclined towards romance."

"You aren't saying you aren't attracted to males," Tsuna pointed out, voice muffled against his back.

"I can be," Reborn said after a pause. "Although I'd much rather a woman to be clinging to me."

"Hm."

"If it's a hormonal thing, you don't ask for much – Dame-Tsuna, did you just bite me?"

"Hm."

Tsuna bit him again, and Reborn wondered if Tsuna thought fabric was enjoyable. He was trying to bite through his shirt, and the boy was far too weak normally to accomplish it. Then Tsuna moved to his neck, and Reborn shoved him away again.

"I said that's all," he said coolly, and when Tsuna leaped forwards, Reborn kicked him away. Tsuna clung to his leg, and that was when he let go.

"Dame-Tsuna?"

Tsuna fell back, and Reborn wanted to take pictures of that blush. Tsuna covered his face, turning and banging his head against the wall. "Oh god, that's...so..."

"I have to say, I am pretty sexy." Reborn smirked at Tsuna. "You have remarkable aethestic taste."

Tsuna was still blushing, feeling like he would die from the embarrassment.

"I suppose it's handy to have a mafia boss under my thumb."

"Hii! I don't want to be a mafia boss-"

"Not even for me?" Reborn arched an eyebrow. "I'll reward you."

Tsuna flushed even more; it was a wonder his head didn't explode. "R-Really?"

"Yes. Only if you do as I say though."

"Y-Yeah?"

"So be a mafia boss."

Tsuna slumped over, still not facing Reborn as he perched on his bed. "So. When did this happen?"

"Um, it just..."

"You must have some idea. Although, the idea of you falling for an infant me is incredibly disturbing."

"It wasn't then! It was when you...intervened the second time," Tsuna admitted. "Y'know, I didn't realise?"

"I'm still miffed, but do continue."

"And then-I-" Tsuna stumbled, then buried his head in his arms.

"Have dirty fantasies about me?"

"Well, yes?"

"Share." Reborn's eyes glinted with something malicious, and Tsuna gulped.

"Um. I thought about us..."

"Yes?"

"...Eating cake on a kotatsu," Tsuna whispered.

Reborn very nearly outright gaped at Tsuna, but as it was he only looked stunned. Tsuna winced under the look, still not checking to see what Reborn's expression was like.

"Were we doing anything else? As in, was I giving you a hand-job or anything?"

Tsuna's head snapped around in horror. "Oh, no, why would I think that? That's gross, Reborn!"

Reborn sighed, then smirked in amusement. "You're so pure. That could be fun to deal with."

Tsuna's flush returned even brighter than before. "What do you..."

Reborn stood, then whacked Tsuna over the head. "Figure it out, Dame-Tsuna."

A sexy prompt (nsfw): Leon creates a new Dying will bullet, so Reborn decided to try it out on Tsuna. The bullet ends up making Tsuna succumb to his hormones. Cue whatever ship you want to flow with. (courtesy of noodleexplosion on tumblr)