He pauses, and the expression on his face fades a little as he does. Only a little though - which means he's still smiling, but in a way that's softer now, rather than anything that seems even remotely close to a smirk.

"Aw, come on." Even that sounds gentle - though it'd be easy to take it in any other way, given what Inigo said only moments before. "I didn't mean it that way."

Since Tidus is starting to bristle now, making Inigo worried that he perhaps pushed the other a little too far. And it's not like he wants to make Tidus feel bad.

"I'm just excited."