A social dust bunny is a person who sits in the
corner and does just about nothing. They aren't noticed by many
people, and often are introverts. Unlike some
people who are noticed just by how silent they are, social dust bunnies are often not noticed at all. They keep to themselves, and that's just about it.
john: hey,
matthew, did you see that kid?
matthew: see who?
john: (gesturing wildly) that kid, i don't know!
matthew: (eyebrow raised) um, i have no idea what you're talking about.
marcus: i think i know who you're talking about.
john: that kid?
marcus: yeah, that kid.
john: see what i mean?
matthew: oh, yeah. he's just a social dust bunny.