Equivalent to cock-blocking yourself.
Poonacide is considered to be any
words or actions that that are an immediate turn-off to the
female of interest, thereby killing any chances of sexual contact.
Comes from the root
words POON and SUICIDE.
Guy 1: "Dude I totally had that
chick until I started talking about my
ex."
Guy 2: "Yeah you definitely committed poonacide there bro. Might wanna steer
clear of that subject next time."