Granny Fart
The act of farting unexpectedly while you are in some some sort of strain. Like pushing yourself up from a chair or lifting weights and blowing ass while you do.
"That dude over there on the squat press totally granny farted, I bet he blew out his intestines"
"My grandma just got out of her chair and ripped herself a new asshole with that granny fart"
"My grandma just got out of her chair and ripped herself a new asshole with that granny fart"