He let's Bucky's slight correction about how Natasha would clean up a kill lay. Because really Tony's no assassin, and he's barely good at murder on the few time's he's had to kill to live. So he chooses to accept that maybe he's thinking a little too idealistically which isn't a good look on him so he's not going to fight it.

He does instead look down at his donuts then at Bucky.

"You know, if you had asked that earlier you could have gotten the exact donut you want."

As much as it sounds like he isn't planing on offering a donut, the fact he points the box in the other man's direction for him to open the box clearly says otherwise.