At your house the smell of our still living human bodies and oven gas
Instead of going with the obvious, I would say that this line does not describe a suicide — rather, it is a play on the theme, as oven gas is a kind of traditional, romantic symbol for suicide (see: Sylvia Plath, the tragic artist).
I think what is being described here is a domestic scene (see: the kitchen towel line later), the oven gas a reference simply to, uh, cooking (domestic life), and the ‘still living human bodies’ a play on it. Despite the oven gas, they (the narrator and the addressed) are still alive. Perhaps it also implies a stale relationship, slowly being drowned by deadly gas.
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