Tony has a difficult relationship with the women who sit at that desk.
First, it was that standoffish witch Vivian, who'd storm off every time he mentioned a movie or made a teasing remark. Unwillingly, but in the interest of getting some actual work done, he'd toned down the smartass comments. She couldn't keep up with the Gibbs way of doing things either, and stormed off for the final time. He wasn't exactly sorry to see her go.
After several years of the desk being empty, a Secret Service agent came along and filled the spot, fixing holes in their family that he hadn't noticed and becoming something like a big sister to him. Kate stood by him, through the plague and everything else working for MCRT threw at them. She didn't mind his movies or teasing jokes, and despite what most other people think, their relationship was completely platonic. (She loved him more than Senior would admit to, after his mother died. She loved him more than Gibbs would admit to, after his family was ripped apart.)
And then she was gone, cold and wrong, and he was the one to tell Rachel, he had to be the one to tell Rachel, and they held each other and cried. Because they were family. Because Kate was gone. Because they both knew that everything was going to change.
When a woman marched up to him and demanded to know if he was having phone sex and then refused to leave, he was smitten. Ziva is the love of his life. She came in like a whirlwind where Kate was a breeze (although Kate was just as dangerous as Ziva, as she'd so kindly remind him), and they began to heal. (It still took a while for him to forgive her for her role in Kate's death, however.)
But then she left, without telling anyone why, and just like that, they were breaking again. He still thinks about that. She knew that his deepest desire was to have a family, to be a better father to his kids than his was to him, but she denied him that by leaving when he thought they were healing, He still has the ring he was going to propose with, he still loves her, incorrect American metaphors and English language problems aside.
There's a reason his goldfish are named Kate and Ziva; they are the two women who left him; he was too young to grasp why his mother was gone when she passed on, but he knew that Katie and Ziva broke something in him when they left.
So that brings them to now. Ellie Bishop. Newest applicant for a revolving door of women. The newest person sitting behind that desk, Katie's and Ziva's desk. And maybe Bishop, with her weird food and blond hair and penchant for sitting on the ground instead of at the desk, would be enough to heal them. Everything about her was so different, so alien, so innocent, maybe it was what the team needed after Ziva and Kate.
Four women behind that desk:
One hated him.
Two loved him.
And he's not so sure about the last one yet.
He'll get back to you on it.
Because hopefully, she'd become his newest little sister.
So yeah. Tony may have a difficult relationship with that desk.
But so did his team.
McGee flinches every time someone mentions Ziva, worried that she'll never come back. He couldn't even look at the desk for months after Kate died, and it took him longer to look Ziva in the eye.
Abby, who couldn't talk about Kate to anyone but Gibbs until a few years ago, yet brought her up with Bishop after knowing her for only a few hours, who still wasn't ready to talk about Ziva not coming back.
Gibbs, to whom Kate and Ziva were surrogate daughters, a strange reflection of Kelly and also not Kelly, two women who he loved as daughters who his daughter would've loved.
Ducky, who enjoyed having someone to ramble to, to impart wisdom gained throughout his long and interesting life.
Palmer, who hadn't known Kate for long but had admired her. He'd thought of Ziva as a friend, going to her for advice when he needed an impartial opinion.
Dorneget, who didn't know Kate and Ziva as well as the others but always had good things to say about them.