If you folks search for the word 'pariguayo,' you'll find my mugshot.
The definition in the Urban dictionary is all wrong. Pariguayo is a tonto, not a bull-sh!tter. It comes from 'party watcher', el t?guere que no baila, no tiene mujeres, no tiene muela.
And it dates back to the Yankee occupation of 1916-1924, when young U.S. soldiers were allowed to go out and party, and the one responsible for the party (the party watcher) was not allowed to drink or dance... sorta like your designated driver today.
So, when Dominicans asked, "Y este t?guere, por qu? no baila y bebe?"
Soldier: "Oh! I'm the party-watcher."
Long story short: Some girl called Berzin a pariguayo. But I doubt it, as Berzin es un tiguerazo del Bronx.