Zack x Cody. Originally intended to be a oneshot, but I got carried away ^_^ There will hopefully be more chapters. Slash/Twincest. First fanfic.

It was warm and sunny that day, unusually balmy for April. It was the day Zack would remember for his whole life. It wasn't the sunshine, or the half day of school, or the afternoon spent at the skate park eating freeze pops and slowly watching the sun set.

No, it was the day he fell for the one person in the entire world whom he wasn't allowed to love. He knew that it wasn't entirely that day, specifically, but it was that day when it hit him, truly hit him, that he was in love with his brother. Twin brother.

They were juniors in high school, sixteen years old, with their entire lives and futures ahead of them. Zack had a girlfriend, Cody was well on his way to having one, and they would be seniors in two months. Everything had been perfect. Up until now; until Zack realized that it was a lie, his relationship with Alicia was a lie, maybe even his definition of himself was a lie.

He remembered every detail of the moment, that moment, all too clearly. It was forever branded on his brain, on the back of his eyelids. He was watching Cody laugh at some stupid thing he had said, drops of bright green from the freeze pop dripping down his fingers, the sun playing on his hair. He suddenly couldn't hear anything but the rushing in his ears, suddenly couldn't see anything but Cody, couldn't feel anything but that swooping feeling somewhere deep inside of him.

"You okay?" Cody had asked curiously, always knowing what his brother was feeling.

"Y-yeah, I'm okay," Zack had forced out, even as Cody's green-blue eyes gazed curiously at him.

Ever since then, determined to ignore the feelings raging inside of him, knowing they were so wrong, so forbidden, he had thrown himself into being with Alicia and his other friends, leaving Cody confused and alone. He stayed at Tom's and Jeff's and Alex's places after school, went to the movies with Alicia, and stayed out late on weekends. Carey tried to ask him about it several times, but he had just shrugged it off and she had let the issue drop.

But he was empty and lonely without Cody. He had never realized how much he had taken his brother for granted, how he had assumed Cody would just always be there, every day, every night lying in the bed next to his.

Cody finally gathered the courage to talk to him about it one night after school, one rare night they were both home, when Zack had been fooling around with the Wii and Cody had been studiously rereading his English notes for the test on Monday.

"Zack," Cody said, making Zack instantly look up at the tone of his voice, and then, blushing slightly, back at his socks.

"Yeah?"

He heard Cody sigh softly, and then the rustling of papers as he gathered his notes. "Never mind."

"No," Zack said, refusing to back down, even though it hadn't been him that had started the conversation.

Cody glanced up again, glacial eyes meeting Zack's, and his hand coming up to impatiently brush a strand of hair from his face.

"Look," he began awkwardly. "Ever since…I don't know. You've just been ignoring me. A lot. Do you even care anymore?" he blurted out shakily.

Zack made himself look away. "Of course I care," he managed, biting his lower lip sullenly.

"Then why don't you ever show it?"

Zack turned back to him, hands clenched into fists at his sides. He imagined saying I love you. He imagined throwing himself at Cody, smashing his lips onto his brother's. But imagination wasn't going to help him. Without saying a word, he walked over to the door, threw it open, and slammed it behind him as he ran down the silent hall and down the stairs. He didn't know where he was going; only that he couldn't take Cody's questions and hurt looks. Cody had no idea. He couldn't have any idea, because what Zack was feeling was wrong. Every part of it was wrong. He and Cody shared DNA, for god's sake.

He threw himself into the cool May evening outside, tying his sweatshirt around his waist, continuing to run, even as he had no idea where he was going. His feet pummeled the sidewalk relentlessly, the thoughts he had tried to suppress for so long coming to the surface. The way Cody's upper lip crinkled when he was upset, the way his eyes flashed when he was happy, every movement he made, each one seeming more sensuous than the last to Zack. He ignored the people, the cars, the city, the movement. He let his feet carry him to Alicia's apartment building, waiting as he was buzzed up.

She opened the door, surprise in her eyes, taking in his ruffled, sweaty condition.

"Zack-," she began, but was quieted as he pressed his lips to hers roughly.

She kissed back, slowly at first, then harder, her hands coming to wrap themselves around Zack's neck, his fingers trailing down her sides, tongue slipping between her lips.

He broke the kiss to gasp "Is your mom home?" and when Alicia shook her head no, he kissed her all the more. Kissed her and kissed her, leaning her up against the wall, kicking the door shut with one foot, hearing her little moans in his ears.

She took his hand and led him to the couch, lying underneath him, stretching her fingers under his shirt. He straddled her hips, kicking off his sneakers, his hand snaking underneath her top, unhooking her bra, sliding her shirt over her head. He tried not to think too much about what he was doing.

Inside her, he realized he felt nothing. Nothing at all. He was blank and empty and cold, and only forbidden thoughts inside his head kept him aroused enough to continue. Every time he moved, he saw Cody's face underneath him. He blocked out her voice, and in his head, he heard Cody's ragged breathing, Cody's moans and whimpers.

Later, with her lying against him, he fought back the tears. He hated himself for this. He hated himself for wishing Cody had been his first. He hated himself for knowing he couldn't tell Cody about it when he got home, as his instinct would have been, hated himself for pushing Cody away to this point until he couldn't tell him anything.

They were two halves of a perfect whole; why couldn't his brother see that? Their thoughts and fears and desires mirrored each other's, they shared everything together, and Zack couldn't ever imagine feeling this way about anyone else. For him, Cody was the end-all. And he hated himself for feeling this way about his twin. It was wrong. So wrong.

It was nearing midnight by the time Zack inched the door open, unsure of what he would find waiting. But to his relief, the apartment was silent, and dark except for the shadows of moonlight thrown on the floor by the gap in the curtains.

He went into the bathroom and stared at himself, at his reflection staring back at him in the glass. He could see the thin crack where Cody had thrown the baseball after being chased around the apartment by Zack. He could see the towels, his tossed over the bar and Cody's primly folded beside it. Cody's shirt was tossed on the floor. He could smell the soap Cody loved. There was Cody everywhere. Little reminders of him and them everywhere, and Zack didn't think he could take it. He wished he'd slept at Alicia's, before remembering the look in her eyes, the one that said "I love you", the one he didn't want to see because of the guilt he felt every time he saw it.

He thought he'd see a difference in himself after losing his virginity, but the reflection in the mirror was the same one that had stared at him six hours earlier, although this version of himself was slightly more rumpled and tired looking. He ran his fingers through his hair and closed his eyes, leaning on the sink. He slid down to the floor, staring at the pristine white tiles and the tan lines that ran through the white, turning the floor into perfect squares. His eyelids drooped once again. He curled himself into a ball on the cold floor and fell asleep.

Zack didn't know where he was when he woke up, the sun hitting unfamiliar places on his face and the cool tile digging into his back. He rubbed his eyes with his palm and slowly got up, the events of last night slowly coming back. He groaned almost silently and slid the bathroom door open. It was early enough that Cody and Carey weren't yet awake, and he was grateful for that.

On his way out the door, he stole a glance at the closed door of the bedroom he and Cody had shared for five years. He wanted to go in there and make everything okay again, back to how it was, Cody as his best friend and himself as Cody's. But he didn't know how. So he let his feet carry him out the door again.

When he finally realized he was starving and still in his wrinkled clothes from the night before, Zack slowly dragged his feet back to the hotel. He slid his key into the door and turned it slowly. He was becoming a pro at slowly entering his apartment, he thought.

He wasn't prepared for Cody to be there, ten feet away from him, lounging on the sofa. He stared at him for a moment, wanting to run away. To be anywhere but here. Cody opened his mouth as if to say something, and then closed it again. He dropped his eyes from Zack's and curled his feet underneath himself.

Zack moved to the kitchen, rummaging around inside the fridge until he found the orange juice carton. He deliberately drank directly from it, wanting to get a response out of Cody, who always yelled at him for doing so. But Cody, lips pressed tightly together, just looked away.

Zack wasn't sure of how it had come to this. How one look in the park translated to weeks of slowly drawing farther and farther apart, until his best friend had become his worst enemy.

He slowly moved to the sofa. "Hey," he said, uncertainly.

Cody looked at him for a moment. "Hey."

"Look-," Zack began at the same time as Cody opened his mouth to say something. They both fell silent.

"Where were you last night?" Cody said at last, breaking the silence.

"Alicia's," he admitted. He tried to imagine looks of jealousy on Cody's face. He didn't think there really were any.

"Oh."

"Yeah." He listened to the silent conversation for another minute, playing and replaying in his head what he actually wanted to say, the words that practically begged to come out. But then Cody stood up slowly, and headed for the door.

"I'm going out," he said roughly, and the next thing Zack knew he was alone again in the apartment.

Tiredly, he stood up and wandered into their bedroom. He sat on Cody's bed, smelling his familiar smell, intending only to stay there for a moment. But somehow he ended up curled in his sheets, fast asleep.