pointing out the arrival of someone who recently hurt themselves in a fall-

"Oh look, here comes Stumblefuck"

ex. (talking to a friend on fbook chat)

person 1: hey man whats going on tonight
person 2: i gotta go to the bathroom il poopt you

or

person 1: whatsup man what are you doing?
person 2: poopting you

Look at that guy, he's all stumblefuck.

When an uneducated opinion starts with "I don't think he's a racist" and turns to fact, "I know for a fact that he's not a racist". Then it's time to label the offending fucktard a "Stumble-fuck".

Jason kept stumble fucking around when he was trying to tell his story