Hey, I was just browsing Youtube, and came across this short cartoon. The premise is that it takes place on a farm where the animals (and even inanimate objects) are suddenly beset by spontaneous inflation. No further explanation is even attempted by the cartoon itself.
At one point the farmer finds that his wife has contracted the same condition and is floating around on their bedroom ceiling. Toward the end, she's blown up even bigger and fills the entire house. Her expansion is all off-screen, unfortunately.
https://www.youtube.com/watch?v=fWkcLW1aPCM