It didn't really take too much to upset Bilbo -- actually, it depended. Unannounced house guests had upset Bilbo, as had unexpected journeys. But... it seemed like he had gotten over both of those things, and had even made friends in the process.
Like Thorin.
So it really depended on Bilbo's mood, what upset him. But Thorin's words? They had not upset him in the slightest. It was starting to take a lot for Thorin to upset the hobbit.
"It is nice to be here," he agreed. "I am glad to be living with you." It was nice. He was starting to grow attached to the Dwarf -- more attached than he had been in Middle Earth.