a 'panama city speed bump' is where you have a girl in a car. she's on top. right before climax you look her dead in the eye and say "i'm sorry but i have insert disgusting STD". she quickly jumps. knocking herself unconcious on the roof of the car. while unconcious..you nut on her face and throw sand all over her, already cum covered, face.
dude...we we're ridin' hard until i gave her the panama city speed bump..