In Eight's defence, Tidus isn't wearing any team colours - someone's got other clothes than the standard they show up in. There's only the purple band of his SCA device, but who even pays attention to those anyway? And Tidus has no suspicions; sure, he doesn't know what the problem was, but when Eight is being like this...

It's hard not to just take it with some fun, and give Eight a pat on the shoulder.

"See? There's no reason to do chores on your own here - that's boring! Ask Inigo to help out if you can't get me. With everything being so close to mission time..."

Ah. "Actually," he interrupts himself, looking at her with a bigger interest, but his smile not lacking. "--You ever tried sticking your ink on that garden wall...window, in that carriage?"