A/N: Not mine, I'm just borrowing them for a bit.
Spoilers: 6x23 Legends Part 2 and minor spoilers for 6x08 Cloak 6x09 Dagger
Any recognizable dialogue comes from Legends Part 2
Trust (n.) – assured reliance on the character, ability, strength, or truth or someone or something
"Did you do that secret thingy I asked you to do?"
"Yep. Rivkin flew out of Los Angeles today unescorted."
"Tel Aviv, with a stopover…in DC."
In the following silence Tony's mind was buzzing with the many possibilities for Michael returning to DC, whatever his reason he knew that Ziva was somehow involved. It was only after Abby had said his name three times did Tony realize she was talking to him. "Sorry, Abs, guess I got a bit distracted there."
"Tony, are you going to tell me what's going on?" asked Abby quietly.
Tony didn't look at her at first. Did Abby deserve to know why he was asking about Michael Rivkin? Yeah, she did. Did Tony want to be the one to tell her? No.
"Look, Abs," he began, "it's better if you don't know, at least not until I'm sure about this."
"You can't possibly be suggesting that Ziva—"
"Don't go there Abby," he ordered her in a tone similar to the one he used when he was talking to McGee earlier.
"This is Ziva we're talking about, don't you trust her?" asked Abby in a last ditch effort to get a straight answer out of him.
Did he trust her? He wasn't so sure anymore. Ziva was many things but before this week Tony would have never thought that she could possibly be a traitor. Then again, he had thought that Michelle Lee was loyal and look how well that turned out, those events still left a bitter taste in his mouth. Ziva isn't Michelle,' a voice in the back of his head reminded him. No, Ziva wasn't Michelle; the two women couldn't be more different but they each had one thing in common, Tony had assumed that they were loyal to NCIS.
"Tony," prompted Abby.
"We're partners, Abby," he told her finally.
If Abby noticed that he never actually answered her question she didn't say anything, instead, she told him that she would go grab her stuff before they would go out for that drink.