a slow realization

A recent conversation between me and my roommate, Muffs:

Muffs: "Hey, is that green loofah in the bathroom yours?"
Me: "Um...yes."
(note: there are only two loofahs in the bathroom and only two roommates in the apartment)

Muffs: "Are you sure?"
Me: ".....Um, yes. I'm sure. I just bought it a couple of weeks ago."

Muffs: "Right...um, yeah, that's what i thought."
Me: "......."