It's where instead of holding your shaft like a normal man, you hold it sideways and wave it about like a gangsta would hold his probably illegal pistol.
Latifa- Jerome! Did you gangsta fap again? There is semen everywhere!
Jerome- Latifa! You know that gangsta fap is the life for me.
Jerome- Latifa! You know that gangsta fap is the life for me.
by Jerome666Gangsta March 23, 2013