"Sasuke's cell is just down the hall to the left." Kabuto had panted against the smooth expanse of Sai's chest after he had thoroughly fucked him, his spent cock still sheathed in Sai's tight orifice. The sex had been amazing, Kabuto certainly wasn't compensating for anything with his intellect, but the fact that he hadn't been harder to get information out of despite being the snake sanin's most trusted companion made Sai wonder just how loyal Kabuto really was.

Perhaps Danzo is wrong about him... Sai thought as he quickly and soundlessly made his way to the Uchiha's chamber. It certainly wouldn't be the first time.

The Root shinobi stood outside the door, wincing inwardly as he crouched down and moved to unroll the scroll. But as Sai moved to paint the snakes onto the paper, he paused. It was his mission to assassinate the misguided youth but at the same time, a curious thought came to mind.

Was Naruto perhaps in love with Sasuke because of the size of his dick?

Sai contemplated this for a long moment before he slowly rolled the scroll back up. With a kunai in hand, for his own safety of course, Sai slowly crept into Sasuke's stone cell. The Uchiha didn't stir at all, even when the futon sank slightly under Sai's added weight. It wasn't until Sai had undone the purple rope around Sasuke's waist that Sai felt a pain resonate through his skull. Calloused fingers gripped his hair tightly and tugged his face away from the cursed boy's crotch.

"What do you think you're doing?" Sasuke's voice was an emotionless, lazy drawl that came out like more of a sigh than anything, yet still holding such dark promises if Sai answered wrong. It sent shivers down his spine and heat to pool in his groin.

When he didn't answer, Sasuke snorted and tightened his fingers. Sai didn't wince. "Konohagakure shinobi, hm? What could Orochimaru possibly want from you?" He mused quietly, mostly to himself. Sai still didn't response so he sighed and continued. "They really must be weak now, to send an assassin only for him to want to suck me off."

Sasuke released his hold on Sai's head with a grunt and leaned back on his hands casually. Sai stared blankly into Sasuke's dead, onyx eyes. "Go on."

Without needing further prompting, the Root pushed Sasuke's white pants down to his thighs. Sasuke wasn't even hard yet but Sai found himself wondering how he was going to get the boy to fit in his mouth. His gloved hand stroked Sasuke firmly, watching with masked wonder as Sasuke's manhood swelled with arousal and flush from the blood rush.

Unconsciously Sai licked his lips. Sasuke certainly doesn't act the way he does to compensate. Sai supposed that just made Sasuke a true, cold hearted bastard.

The cursed boy's girth stretched his lips as he took Sasuke into his mouth, the action eliciting a low sigh from the younger boy. Sai bobbed his head slowly between Sasuke's legs, giving him time to adjust to Sasuke's size and relax his throat. Once he felt he could bear it, Sai took all of the cock in until his nose was tickled by Sasuke's pubic hair. At some point his hands came to rest on Sasuke's thighs and he could feel the muscles contract beneath his fingers; the only indication of the boy's pleasure.

Just as Sai began to feel his jaw get sore and he went to move away, Sasuke's fingers suddenly tangled themselves back in his inky locks and his hips surged forward. Sai made a muffled noise of surprise that was drowned out by Sasuke's own groan and fought his gag reflex so he couldn't choke because of the sudden rough treatment. Breathe through your nose, just breathe. Sai told himself as Sasuke kept his head in place and fucked his throat. Despite the abuse, the ache in his jaw wasn't the only thing growing.

He thought for sure that Sasuke was going to come right there and force him to swallow the load, but instead Sai found himself sprawled out at the foot of the bed. His jaw was slack and lips swollen and slick, but his breathing was hardly as ragged as Sasuke's was. Almost as quickly as Sasuke had pushed him away, he reached out to pull him back, their positions switched as the Uchiha boy pinned the Root beneath him.

Sasuke didn't kiss him, he bit him. Wherever Sasuke's lips touched his skin he left bruises and indents in his wake. Sai didn't mind, he arched towards the violence and invited it. The Uchiha's body language couldn't be any clearer. Sai was not going to be able to walk and report back to Konohagakure even if he wanted to.

With no regard to Sai's clothing, Sasuke tore at the black fabric as if it were the most offensive thing he had ever seen. Then flipped Sai over once he was completely naked and without even bothering to prep Sai, he was still stretched and slick from his encounter with Kabuto after all, forced his entire length into the lean shinobi. Sai mentally thanked the medical-nin for his care before sending him off to Sasuke.

The Uchiha lost himself hurricane of lust and violence and Sai couldn't help but think it was so unlike him but so much like a certain blond boy.

As Sasuke's thrusts grew more urgent, the air around them shifted and surged with chakra. Sai turned his head to the side and his breath hitched as he realized the cause. Sasuke had activated his Sharingan and now Sai was staring with almost comically wide eyes at the illusion before him.

Sai watched as his doppelganger moaned and whined beneath Sasuke, watched the way he greedily took Sasuke's cock into his body, the way his hips snapped back automatically to force Sasuke in deeper. It took him a moment to realize that everything his doppelganger was doing, he was doing as well and his moans were loud in his ears as were Sasuke's. The combined effect was enough to bring Sai over the edge with a loud gasp. His clenching muscles made Sasuke swell inside him and after a few more bruising thrusts, Sasuke groaned in completion and filled Sai with his seed.

Together they rode out their orgasms until Sasuke finally collapsed on top of the other teenager, both of their pale bodies slick with sweat and blood, panting for breath. Moments passed before Sasuke finally pulled out of Sai and watched with a blank expression as a mixture of his essence and blood leaked out of Sai's abused hole. The paler of the two could almost feel Sasuke's smirk burning into his back and he knew it was because of the sticky mess of his sheets.

The Konohagakure shinobi listened as Sasuke put himself away and fixed his clothes before leaving the room. He had failed his mission. Rather than assassinate the renegade Uchiha, Sai had let him fuck him mercilessly into his futon.

Sai couldn't bring himself to care.

As his eyes closed and he drifted off, he decided that yes, the reason Naruto was so infatuated with Uchiha Sasuke was because of the size of his dick.