A donk rocket is when you are having anal sex and the person you are screwing farts, causing your penis to shoot out like a rocket.
"Dude, I shouldn't have let Annie eat beans last night."
"Why not?"
"She got really gassy and donk rocketed me like 5 times."
"Why not?"
"She got really gassy and donk rocketed me like 5 times."
by petifatpapy October 18, 2009