The "S Word"

Having dinner with the family tonight and the little dude announces that he knows what the "S word" is. I was thinking to myself, "oh shit...." My dude is in kindergarten and my little girl is a year behind that... how the heck do they know what the "S word" is already!? Doesn't that seem young to you? I asked who told him and he told me that several friends told him; naming Lex, Max and a few of his other buddies. He then said, "daddy, do you want me to tell you what the S word is?" I said, "sure, why not...?" "Stupid" he said. Ohhhhhhhhhhhhhhhhh, that S word. I then got real serious and told him how wrong it was to use, etc....