When ones' scrotum extends longer than their testicles. Thus causing an excess of skin to hang from their penis. This is a very common incidence for men past 25 years in age. The skin itself also may slap against ones' leg in the event on a high speed situation, and some loose clothing.
"Dude did you see that guy in the changeroom?" - Guy 1
"Yeah man, he had a huge elephant ear. You could totally see his overhang" - Guy 2