A speaker tells a lover she is his "everything," and she laughs it off: she's not his chair. The poem takes her joke seriously. If he can't stand on his own, he asks, where else would he sit? From there he builds a house out of her: chair, table, bed, pillow, closet, dresser, even the basement. Nothing is spared, and that includes the unpleasant parts. The musty smells and seeping water suggest he leans on her through his own troubles and fears too, not just the comfortable moments.
The feeling is tender but also vulnerable. His love is real, yet it sounds close to dependence, as if without her the place would be bare. The closing lines make this clear. The furnishings are so ordinary that the room might look empty, but for him, everything he has is her. The mood is warm, humble, and a little fragile, with a quiet humor that keeps the confession from becoming heavy.