Tidus doesn't have to tell him twice. Inigo is immediately stepping back, absolutely determined to be outside of the blast radius, if he can help it at all. It's why he doesn't even stand close to Tidus, instead a few decisive steps behind the human and higgledy pair.

He's staying dry, thanks. No Splash Mountain for him, pals!!

Once he's sure he's going to be safe, he calls out towards the man moving in their direction.

"Roland, hurry..!"

Not that Inigo truly thinks Tidus is going to prematurely fire now, but..

.. well, you never know what could happen. Especially if a higgledy happens to get bored!