maaaan
When someone does something so stupid it makes you want to punch them. You yell shut the fuck up because you're too mad to be polite.
Maaaan, you tried to talk to a chicken and it ran away. Shut the fuck up!
Maaaan, you said you could beat up a bull and then cried. Shut the fuck up!
Maaaan, you tried to ride a bicycle with your hands. Shut the fuck up!