"Anything?"

His tone slides all the way back into regular levels of Inigo for a second as he repeats the word. Apparently it just startled him that much. Even if Tidus is just joking about it, or it's part of their little game here, that's still a pretty dangerous thing to offer when he can call him out on his bluff.

And considering the severe gay panic Tidus is causing him here, he can't quite resist that temptation.