As Kakashi settled into bed that night, he glanced at the window-and started.
Tonight was the full moon.
The night Itachi always came.
Kakashi quickly swung his feet over the edge of the bed onto the soft carpeting of his apartment floor. He shivered in the chilly night air; he was wearing nothing but a pair of loose sweatpants and his mask. He strode over to the door, checked the lock, and just as swiftly checked the windows and swung the drapes shut. He knew the efforts were futile; but at least he might know if Itachi was coming.
"Afraid, Kakashi-san?"
Kakashi whipped around so fast he almost fell over. As it was, he lost his balance and fell forward, directly into Itachi's chest. Gasping, he skittered backwards, trying to put as much distance as possible between him and Itachi. Itachi laughed as his prey hit the wall, and advanced on Kakashi as the jounin trembled in fear. "So you are afraid-I never would have thought you would show it."
"Th-Think about who is standing in front of me with the full intent of harming me without restraint or scruples," he said, trying to slide back along the wall. Itachi chuckled and threw his palms to the wall, trapping Kakashi in a human cage. A small noise of fear was emitted from Kakashi's throat, and he did the only thing he could: he sank down onto his haunches. Itachi smiled and leaned over.
"It almost makes me feel bad," he murmured, tipping Kakashi's masked face up to his own. Kakashi yanked his head away, trying to avoid the cruel Mangekyou Sharingan now hovering over Itachi's normal Sharingan. "You're so innocent...stripping that away will be fun."
"You already have," Kakashi shot back. He knew what was to come next: Itachi had done this to him before. Itachi grinned and slid his hands down Kakashi's sides, stopping at his hips and tightening his hold. "Let's go," he said. "The sooner you get this over with, the better for both of us."
Kakashi fought viciously against Itachi's hold as he was pulled up into a tight embrace and pressed up against a strong body. Itachi didn't even seem to notice, let alone care, which only humiliated Kakashi even more. He re-doubled his efforts, and this time Itachi did take notice of his struggles.
What happened next Kakashi couldn't really absorb. The next thing he knew, he was flat on his back in his bed, with Itachi pressing up against him with a lust Kakashi had only ever seen before on nights like this. Itachi took Kakashi's hands and pinned them above his head, ignoring Kakashi's still-violent protests. He used his other hand to hold Kakashi's head against his own, and he kissed him. Hard. Hard enough to leave a purple bruise on Kakashi's face underneath the dark-colored mask. Itachi grabbed the mask in his teeth and yanked it down, exposing Kakashi's pale, fearful face and trembling lips.
Kakashi's words were halted by Itachi's lips, which were now pressed up against Kakashi's. Kakashi tried to move away, but was caught by Itachi's free hand and forced to endure the kiss. Itachi sighed with pleasure; Kakashi was the only person he would ever love, and the only person he had ever wanted. He finally broke away, allowing Kakashi a shallow breath before he kissed him again. This time, he began roaming Kakashi's neck, searching for the right spot. He found a scar, no doubt from one of their previous battles, high on Kakashi's neck and brushed his lips against it. Kakashi cursed himself as a breathy moan escaped his throat. It was more pain than pleasure, but still, it was a response. Itachi smirked and deepened the kisses over the scar, extracting another groan from Kakashi. Itachi put that to memory; the scar on his neck was sensitive. Kakashi began to struggle again, and Itachi decided that he had taken enough. He plunged his tongue into Kakashi's mouth, completely overpowering the jounin. He was going to have him-and he would learn to like it.
"You belong to me," he murmured, pulling back. "And you will learn to like it."
Kakashi's only response was a surprisingly strong yank against Itachi's hold on his wrists. Itachi simply tightened his hold, and Kakashi could feel the veins in his wrists losing circulation. With a small whimper, he lay still again. Itachi loosened his hold.
In the slight moment that Kakashi was distracted, Itachi had slid his pants off and was throwing aside his own clothing. Kakashi realized in an instant where Itachi was going with this, and he immediately attempted to pull away-
-half a second too late.
Itachi had released his wrists and was now taking his hips in a powerful, vise-like grip. Kakashi screamed and tried again to get away. In a last-ditch effort, he swung at Itachi's head with his now-freed hands, but Itachi simply ducked the swing and kissed Kakashi again, silencing him as quickly as he had before. And one that was done, he plunged into Kakashi, not caring how much pain he was in.
He was going to have him, and he would learn to like it.
Kakashi tried to scream, but was smothered by Itachi's kiss. It hurt, to be claimed and dominated this way. He knew now he would never get away, not until Itachi let him. And from the way things were going now, that would be a very long time. Itachi loved how his victim tried to scream in defiance of him underneath his hardened body, but he refused to let him. He was his, and he would do whatever he was told to do. Itachi knew Kakashi was in pain, but he liked it this way. Even if he got a little more submissive every time, he would still resist him, and Itachi would simply overpower him and make him his own.
Finally, Itachi collapsed on top of Kakashi, who was now in tears and still fighting. Itachi remained with him for a little longer, resting until he had the strength to pull himself away. "You're wonderful," he murmured into Kakashi's hair, after removing his lips from Kakashi's. Kakashi just lay still, only wanting him away at the time. Itachi granted him his wish; he pulled away from Kakashi and sat next to him on the bed. Both were drenched in sweat and exhausted, but Itachi still managed to wrap Kakashi in his sheets and pull him into his arms. He held him against his chest, telling him to cry and that it was all right and he would let him. And Kakashi would clutch at Itachi's shoulders, afraid of being thrown back and fucked again. Itachi smiled; he had finally fully claimed Kakashi, and he was his.
But he would never really learn to like it.
Itachi left Kakashi asleep in his bed, still wrapped in the sheets, face pressed into the pillow, trying to hide his tears. He didn't bother with the door-he flung open the window and jumped down. As he landed, he heard footsteps, and the sound of Kakashi's door being opened by force. Grinning, he leaped away, using the shadows of the trees to grant him a place to hide.

Iruka burst into Kakashi's apartment, having heard the screams and the noises. He froze when he saw Kakashi on the bed, covered in nothing but his sheets and trembling in fear. Tears streamed down his face and he looked ready to faint. He was only able to force himself to his knees before collapsing again. Iruka darted forward and caught him as he fell.
"What happened?" he asked, shocked that Kakashi was even crying. Kakashi simply buried his head in his shoulder and cried. Iruka knew what had happened even without asking, but he had wanted to see how badly Kakashi was traumatized. And this was bad; the worst he'd ever seen him. He set him down, got him a pair of pants and a shirt, and told him to clean himself up and get dressed. Kakashi meekly obeyed; they had done this before. Iruka would take him home and let him sleep at his house in the spare bedroom for a few nights, until the trauma wore off and they were certain Itachi would not return, and then Kakashi would return to his own apartment. Iruka quickly changed the sheets and tossed the soiled ones into the dirty laundry pile in the closet. Kakashi emerged a minute later from the bathroom, and Iruka handed him his mask. He put it on and let Iruka carry him back to his apartment, through the back streets of Konoha.
Kakashi fell asleep in his arms.

A/n: Bleh, I wanted to play around with lust a bit. It was probably crappy, but you can be the judge of that. Like all good things, this came to me in algebra 1. And for all those wondering: this is not a KakaIru. Iruka is simply a best friend helping out. If you still don't think so, have it your way, but don't flame me. I will laugh, throw coal at your ass, and delete your flame comment!