"You were locked up in here before then," Gen thought aloud, thinking of Senku and what he was apt to do when irritated or upset, which he would only admit to under a process akin to pulling teeth.

Whelp. Time to put his dental smock on.

They were relaxing and having a pretty good time, before Taiju came up. A reminder of home? Someone saying something stupid like he used to, acting familiar? Or someone acting unlike Taiju - dumb, and their heart wasn't in the right place? ... Speculating was pretty useless.

"Someone said something dumb, not unlike what Taiju does," Gen guessed, based on the available evidence, "except, since they don't know you nearly as well, they acted dumber in a different way."