Azami-san is the disinterested one, not the innocent. She really didn't care about the situation. So she didn't fight over it, and this had a lap available save the others were standing up and not eating.
I'd still be offering my lap for the next rotation instead of arguing like those two. Maybe offering to let her try some of stuff on my tray as well, in return for some of hers.
Tsu...Tsukushi Duty...Hey, your lap okay?WHY!?No... I, the childhood friend, shall!You two haven't finished eating yet, right?Sure, whatever.'ya can leave it to me!No two ways about it then...How nice...Sure, whatever.
