A/N: Hi, this is my first time writing a fanfic, so feel free to correct me if there's anything I've done wrong. Also, if the smut scene isn't up to standard, I'm sorry, I have no idea how to improve on that. This story originated from a prompt on rebornanon on LJ. Should I add the link? As in, would that be allowed?

Oh, and, the Arcobaleno aren't babies here, but their adult forms.

Disclaimer: KHR belongs to Amano Akira~

"Dame-Tsuna, I'm going out to get coffee. Colonello's coming over for a visit, so you keep him here until I get back, understand?"

This statement was accompanied by the aiming of a handgun in Tsuna's face, so he had no choice but to nod his head. In a few minutes Reborn was gone, leaving a shaken Tsuna to his paperwork, alone in his office, muttering to himself, "That spartan, he could have just asked, but nooo, he always has to threaten me..."

About ten minutes after Reborn left, there was a knocking on the door. "Enter." Tsuna wondered who it could be, then realized, from the mop of blond hair and camouflage band, it was Colonello.

"Yo, Vongola!" The ex-COMSUBIN soldier greeted Tsuna cheerfully, before settling himself into a chair. They made small talk for a short while, before proceeding to discuss business matters, then finally wrapping up. That took about half an hour, at least.

The memory of a gun cocked at him made Tsuna remember what Reborn had said before he left for his coffee. Figuring it best not to mention anything to Colonello (in case he threatened Tsuna too and left him to be tortured; he was a sadist just like Reborn), Tsuna opted to delay Colonello and hope that Reborn would be back soon.

Thus he was racking his brains for topics to chat with Colonello about, but drawing a blank. It was to his surprise when Colonello speaks up first.

"Aren't you going to eat, kora?" With a start, Tsuna realizes it's already past lunchtime. He shakes his head fervently, then decides to turn it into a chance. "Uh, Colonello-san, you want to eat lunch with me?" The blond only smirks, and with a sinking feeling of dread, Tsuna recognizes that as The Look when Reborn comes up with some sadistic idea to torture him with.

"Come over here, kora," Tsuna looks at him quizzically, then stands up and stretches before walking in front of Colonello. He's unprepared when Colonello pulls him down, and lands on all fours, hands shooting out to stabilize himself. Luckily the floor is carpeted, so it doesn't hurt too much. "You're too trusting, kora. An ally could sell you out and gun you down while your defenses are down, kora." Tsuna only stares at him, then stutters, "Um, Colonello-san? I understand, so could you let me up?"

The blond's hands are settled firmly on Tsuna's shoulders, and he just smirks at the brunet. "Hey, you wanna eat a banana?" This question leaves Tsuna flabbergasted, because as far as he can see, there are no bananas in sight. Colonello stands up, unzips his pants, and lowers his boxers, pulling out his dick.

Tsuna, stunned and still kneeling on the ground, finally understands what Colonello meant.

Colonello sits back down on his chair, and grabs the back of Tsuna's neck with one hand, the other holding his penis steady. Tsuna, thinking that he should make some kind of token protest, opened his mouth, only to get shoved onto Colonello's cock.

'Ah, what the hell, Reborn wanted me to keep him here anyway...'

With that thought in mind, Tsuna tentatively leans forward and sucks, hearing a faint noise of approval from Colonello. He loosens his jaw, then proceeds to lick forward on the blond's cock. Slowly, painstakingly, he manages to envelop the blond's whole cock in his mouth. Continuing his ministrations, the brunet uses his teeth to lightly graze, and his tongue to lick and swirl around the cock. The quiet moans and hand that is now embedded in his hair encourages him that he's not doing too badly. Tsuna balances himself; left hand pressed on the ground, the right moving to rest on Colonello's left thigh. He bobs his head, slowly, before hollowing his cheeks to the best of his ability and then sucking.

The only hints Tsuna gets that Colonello is near his climax is the tightening of the hand on the back of his head, and the hard thrust into his hot mouth, before the blond comes with a rather vocal moan. The liquid hits the back of Tsuna's throat, the taste and the cock making him gag slightly, but he swallows it down anyway. He looks up at Colonello and licks his lips, maintaining eye contact all the while. Colonello chuckles, a little breathlessly, then speaks up.

"You ever done that before?" Tsuna shakes his head, which leads to Colonello laughing for a few moments, before saying, "Well then, you're a fucking natural, kora." With that, he helps Tsuna up, then snags a piece of tissue and wipes his cock clean. With another piece of tissue he wipes the Decimo's mouth clean of any traces of his cum. The tissues are disposed of, and he tucks himself into his clothes, straightening them as well. The Vongola Decimo glances at the clock; Reborn should be back any minute now... And at that thought, Reborn strolls into the office, a cup of espresso in his hand. He smirks at them, then addresses Colonello.

"You lost the last bet, pay up." Colonello grumbles, but pulls out his wallet and counts out a wad of money, handing it over to Reborn. On his way out, he winks at Tsuna and says, "You should show Reborn what I just taught you, kora!"

This makes Tsuna blush, Reborn raise an eyebrow, while Colonello leaves the office snickering.