Tidus was looking at his hands, trying to figure out how to either switch which arm was cradling the candy to give Inigo its hand (it's on Inigo's side), or if he should turn around and give Inigo his hand like that.

...and the look he gives Inigo when he says it's metaphorically is still dubious. Are you sure, bro. Are you sure.

"Give me the candy bag. You still have it, don't you?" Can he stick this candy in there, please. Even if it mingles with the untarnished candies that Inigo still has left!

"You still have to start. It was your idea! Princes firsts," he adds with a chime.