They probably said to each other "this guy is a prick"Ok, got it. I'm still bugged why the two Persian sisters looked at me and spoke to each other in Farsi. I asked them in English what they said. They answered in perfect English: "Oh nothing, just sister talk".
What the heck is "just sister talk"?
This is the reason I don't travel to countries where I do not know the local language.
It is an uneasy feeling when locals look at you and talk in their language.