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."