Ah, yes, the p-word. The feminine version of that is reputed to be the worst thing to call anyone, female or male, in Spanish. There were a few guys who thought it might be funny to call me that, assuming I wouldn't understand, and that of course ended up with me chasing them down the street, screaming, "Toman jabon, pendejos!" (Eat soap, stupid people!!!) I had to keep it mild, because I was there on a church mission.
There is also no insult or swear that can't be made worse by adding the p-word. It's one thing to say, "Go F your mother." It's another to call her a prostitute in the process.
Another mild swear I know came in handy when I had to deal with a white supremacist who wore a button claiming pride in his Irish heritage. So I started talking in what (little) Irish I know. He didn't understand. I then said, "Well, pog mo hoin (kiss my ass), poseur."
He still didn't understand that. (And I thought ever Irish-American kid knew at least that much!)