B-baka don't make eye contact with him while we're doing this!!

That is to say, don't mind how embarrassed Tidus will continue to look, but he attempts to focus on Taiki's explanation before any of that. Humming in understanding, a detail he didn't know about Taiki's whole...world set-up.

"I see... well... I didn't mean anything against them. I just meant, you know- all the different worlds of us there are. Apparently? Weird to think about, but..."

But, well, it's clearly a thing with the same-faced (and named) passengers they meet on the train.