Neji was looking for something he wouldn't find.
The ANBU headquarters was never in the same place for more than a week, to prevent spies from having enough time to call in reinforcements that were sufficiently strong enough to overpower the ANBU members they might find. And Neji was trying to find it.
He'd gotten fed up with the elders of the clan, berating him for letting this dalliance go on as long as it did. He wasn't ever going to have children that would be able to take over the head family anyway—and he didn't want to subject them to the same things that he'd been forced to endure. The pain of knowing that in the end, all you were to your family was expendable. And now he was looking for Itachi, knowing that this was the time that the other was training or being briefed in the ANBU headquarters, and that no one, shinobi or otherwise, could find it unless they were a member.
Shadows flitted overhead and he activated the Byakugan, catching a glimpse of the telltale Zodiac masks. Debating tailing them and realizing that it'd be useless as they'd detect him immediately, Neji instead drifted in the general direction, hoping to see more and to appear as just out for a walk. He did glimpse more of the black-and-white streaks, eventually finding himself in the warehouse district. All of these seemed abandoned, locked up, and he wandered among them.
"Hyuuga Neji. Strange place to be out for a stroll."
Turning, he saw a masked ANBU standing behind him. Neji got the sense that Itachi had been tailing him since he started drifting in this direction. "I was looking for something, Yuki." It felt strange not saying Itachi's name, but there were protocols to follow.
"Oh?"
"Something that can't be found.
"...come with me, Hyuuga Neji-san. I am going to cover your eyes and trust you not to use the Byakugan."
Trustingly, the Hyuuga let his eyes be tied with a strip of black cloth and carried by the older man. It seemed they'd been going an hour before they stopped, and he was lowered to the ground. They were inside a room in one of the warehouses, where the headman's office would be if it were occupied. Outside, the ANBU collected their missions and departed, or checked back in from missions. Itachi removed his mask and put it on a desk nearby.
"Is something wrong?" he asked, leaning back on the desk.
Neji tried to put his troubles into words and found he couldn't, because here and now, it was a thousand years and a thousand miles from here. It was strange, finding oneself reliant on another for well-being—but when he thought about it, he realized Itachi felt the same way.
"Not anymore," he said. "I just wanted to visit you at work."
Itachi raised an eyebrow but didn't say anything. "You aren't seeing much today. It's been fairly slow lately, we're really just practicing. Many new members arrived with the last exam."
Itachi changed into street clothes and they left, wandering the streets for hours talking about nothing and finding comfort in everything. The Uchiha seemed to have a tacit understanding of Neji's problems and steered them away from the Hyuuga compound as much as possible. But eventually, Neji had to go home. Outside the gate, he paused.
"Neji," he said slowly. "If you ever need somewhere to go to get away from your family…my window is the third on the east wall of the main Uchiha house. My parents will take care of you if I am out on a mission."
"I—"
"Don't. Clan families are shit." Something strange glinted in Itachi's eye. "I wish sometimes that I could kill them all."
Neji stepped away from him and opened the gate. "They're family," he said quietly. "They would always haunt me."
In their beds that night, they finally realized that they'd had their first argument.