The fat stomach of a woman that hangs over the belt (sometimes referred to as a Dunlap) so that it looks like she is wearing an innertube underneath her shit
(looking at a girl with this particular issue) yo bitch, no one's goin swimmin, whats with the fuckin innertube!
A large fart housed in the large intestine, often rumbles. a very long and loud fart that sounds like a flat tire on the road.
I got an innertube going on in my belly. that wasn't a fart it was an innertube. I thought I had to take a huge dump, turned out it was an innertube.