Inigo awkwardly stares between the two others as he first listens to Roland's diplomacy speech, and then watches Tidus's.. well, very Tidus-like reaction to it. He's unsure of what to say, and so Inigo remains where he is for a moment, like the water is protecting him from having to deal with any part of this situation.

It's just hard. Roland's explanation is the perfect excuse for Inigo to use, and yet it kind of feels wrong to go along with it. It'd be a lie, after all. Inigo's words weren't just solely in admiration for how hard Tidus worked to earn that body - but this seems like the worst possible moment to have the dad-I-am-extremely-gay talk with Roland.

So Inigo doesn't say anything to it. He just waits until Roland arrives at those last words. It's only then that he shifts in the water, shoulders slowly rising from the surface to join his head above the water.

"Y.. You can stay if you want to." The same response as Tidus, but as often happens with them, the complete opposite emotional undertone. Especially since even as Inigo says those words, his puppy eyes directly aimed at Roland clearly convey please stay. He doesn't want to leave with the awkward that would emerge between him and Tidus if they were left alone now!