They won't make fun of their friend right now--'least, Tidus won't. There's more of a risk of playful teasing from him than there ever is Taiki, and as for the time being--

"You got it! Just keeping kicking-- but you don't wanna kick too fast. But you've got the hang of it!"

--he's here to give all the words of encouragement a guy could need. Good thing there's no worry in these temperatures of any muscles stiffening up. He's floating, watching and waiting on everything Inigo does.