Kaplunking 

its pointing your cock straight down, (using your hand) as you stand and inserting it into a womans vagina

i love kaplunking

Kaplunking by PJmuvaDJ December 16, 2009

Kerplunking 

Where one or more people hang from a miscellaneous object.

Lucy and Adam were sick of planking, so instead decided to try out kerplunking.
They kerplunked from a tree branch.

Kerplunking by whitechocolateladybird July 20, 2011