A tag to "About Face" right after Ziva does her all done by whom when it was done undone speech and Ducky says:
"Don't you understand the Queen's English?"
"Yeah, but not this queen."
THE QUEEN AND THE COURT JESTER
Tony DiNozzo was confused. He wasn't exactly unfamiliar with that state of being but this time he was confused about someone he thought he knew pretty well. He'd been working with her for 3 years after all. He trusted her with his life and he knew she trusted him as well. That hadn't changed. But something had. Something was gone.
It had really come home to him during the whole serial killer/undercover/one night stand thing a few weeks back. She had turned down his offer to help share her burden. Hell, she had slammed it back in his face like she'd slammed his hand on her desk when he'd only attempted to touch her hair.
They had had an easy, teasing relationship with an undertone of sexual tension to it. She brought sunshine to his day often enough even if it was in the form of a joke at his expense. But then it had started to change. It was his fault, too. He knew that. It had started during his undercover assignment when he'd begun dating Jeanne. McGee had told him how worried Ziva had been about him, afraid he'd somehow had some kind of relapse of his pneumonic plague. But he couldn't tell her what he was up to. Hell, he hadn't even told Gibbs. Surely someone trained by the Mossad could understand undercover work and the need to know. And worse, the whole damned thing had ended badly. The only way it could have ended, really. He'd known that from the start. It was a relationship built upon lies, every single step of the way. He'd hurt Jeanne and he'd hurt Gibbs and he'd hurt Ziva.
Or maybe it started even before that; started when Ziva called Gibbs back from Mexico when she was in trouble; when she hadn't turned to him, her team leader and partner. He had to admit that had hurt. And by the time that had worked itself out he was with Jeanne and Ziva had taken a back burner. His job and his entire NCIS life had taken a back burner.
He had chosen them over Jeanne. What choice did he really have? They knew him for who he was. Jeanne didn't really know him, Tony DiNozzo, at all. Yeah, he'd let her inside his heart but she didn't know what he did, how he lived, and that was part of the essence of Tony DiNozzo.
So now he could still tease McGee. He got headslaps from Gibbs, hugs from Abby. But with Ziva it was all changed. The easy way they'd had with each other was gone; now it was like they were just coworkers, never friends.
It had all come to a head when Hoffman tried to kill her. She took it hard and he wanted to reach out and help her but she turned away. All he could do was poke and prod at her until she exploded.
But even that had been better than it was now. At least then she showed him some feeling. Now she was polite, cool, laughing at his jokes but not in on them. She was indifferent to him. She treated McGee like a little brother but him she kept at arm's length behind a wall of polite smiles and impersonal interest. She still did her job and she still had his back but the special connection between them was gone.
He felt like he'd lost something precious that he'd never had the courage to claim. It hurt and he was confused by the hurt and confused by Ziva and he didn't like being confused but he had no idea what to do about it. So being who he was he would continue to poke her and prod her and make her mad enough to strike out at him and maybe he could figure out how to get the connection back.