When he’s upset at someone, Ross will often give a hand gesture where he hits his fists together. I think Monica explained it best in episode [4.05]: “It’s this dumb thing that Ross made up because he was trying to fool our parents. It’s a way of giving the finger, without actually having to give it. I remember I cried the night he made it up, `cause it was the first time that I realized that I was actually cooler than my older brother.