He never thought he'd miss Tony. The other man was always teasing him, calling him McGeek and McGoo and a hundred other derogatory nick names starting with Mc. Not to mention calling him probie and doing dumb things like supergluing him fingers to his keyboard and throwing balls of paper at him when he was trying to work.
That is until Tony was out on sick leave. He and Kate got more work done that way certainly, but not having his senior field agent made Gibbs crankier than usual. He had been head slapped at least 7 times the first day after Tony left isolation and Kate had been slapped 3 times. And Gibbs wasn't the only one in a bad mood. Abby was way more hyper and worried then normal and insisted on checking their mail before it was opened. And he suspected Kate was worried, though she didn't say anything about it.
He had to admit he missed Tony, more and more and the days ticked by. He couldn't come up with a logical explanation. Tony was never nice to him or anything. Except that Tony was like a big brother. Showing his dominance over Tim while looking out for him and deflecting Gibbs' wrath. Not to mention that it was his fault that his big brother had nearly died.
So when Tony came back, Tim made a promise to himself to enjoy having the senior agent around and not take him for granted. Even it if Tony drove him crazy.