coina in slang
what does george lopez mumble under his breath on the show all the time?? sounds like raput??
In some places they (guys pretty much) say "hijueputa" (way to our ears) - meaning any variety of curses, son of a b*tch literally. I would bet this is what he's saying.
I've seen a few shows where he mumbles coño which is a spanish swear word. The closest thing I can think of is puta, which is like whore.