Yeah that's what I'm most curious about.

Is this an oblivious anon posting about something that happened and that he doesn't understand?

Is it a self-aware anon that did do this but understood it to be an awkward and divisive (for bro and sil) but is playing an ignorant persona for the lulz in RL and on 4chan?

Or is this someone who experienced something like this from another perspective and is posting as if they were the moocher?

A fantasy played out by someone in that position who looked for snacks and then thought about how funny it would be to request they buy more food for him?

Or is it purely a creative writing exercise?

Like I think there are people like many of these completely self-oblivious and entitled people out there, but these stories seem to include all the necessary information to at least entertain, which suggests the author is aware of the layers that seem hidden to the character they are writing about.

Doesn't really matter in the end but it can be fun to think about.