Just imagining after missions skk grabbing food together. Dazai not ordering enough (cuz he doesn’t really like eating) and so Chuuya orders some extra and then shares it under the guise that he’s really annoyed Dazai is taking his food. It’s how he gets Dazai to eat more even when he can’t be bothered to argue about it.
Chuuya usually over-orders a bit anyway. Call it a symptom of still remembering what it felt like to be starving, wholly empty, at the age of 7, or even in the years following, after food had become much more stable for him (which isn’t saying a lot when you started out not knowing what bread was), when he still couldn’t quite eat his fill.
Now that money wasn’t an issue, food wasn’t either. Except that his shitty partner insisted on eating like a bird rather than a boy. No wonder he was so scrawny. And yet, why was Chuuya the one still not growing? It wasn’t fair.
There was always that loophole though, without arguing, or with only pretending to argue, if Chuuya let Dazai steal some of his food then acted annoyed, mysteriously Dazai would eat til he was so full he complained. Chuuya tried not to smirk too obviously at that, whenever he attained his goal, covered it with a vindictive laugh instead and a “that’s what you get for stealing my food” as if that wasn’t the intent the whole time. This was one thing he wasn’t sure even Dazai had figured out, after all this wouldn’t be a natural assumption to make based off their relationship. And if Dazai knew, then Chuuya wasn’t sure he’d still play along. So turns out the teenager didn’t know everything. Go fucking figure.