Fum

When you fart on a soft cloth seat and the cushion takes on the smell.
Fum can last for days releasing itself slowly as the gas expells overtime - or - Fum can release in a quick poof upon a heavy seating.

Damn. Did you just fum the couch?

Brynn laid a nasty fum in my mattress last week. It still gives off a whiff whenever I hop into bed.