When a dude pulls his hairy balls out of his zipper and attempts to walk around the bar and pick up unsuspecting chicks. The irony is that he is actually using the only brains that he has!
The act of pulling one's scrotum (testicles included) through the opening in one's pants or shorts, thus exposing the beauty of one's gonads for all to admire. Named for the remarkable resemblance of the display to a human brain, hanging in the breeze.
Dude was hanging brain at The Coney for almost an hour before he got busted by some chick drinking Yeungling.
This commonly occurs when you lean back and put your legs up, while in a seated position and you're rockin short, loose-fitting bottoms, i.e., short shorts or short swim trunks.
Being stoned helps, too.
This occurs with a much higher degree of frequency in wearers of boxers than in wearers of more supportive undergarments.