As I've mentioned before, my next-door neighbor runs an in-home daycare. Some of the kids recently picked up an off-limit phrase from one of the other kids, who tells the following story:

My daddy was driving and he hit a car and he was mad and he said, "Oh, s&%$!"

Boo was listening as several of the kids swapped this story (to the horror of my neighbor, who was trying to explain to them that there was an off-limit phrase without saying it herself), but amazingly enough he didn't pick up the phrase. Which is good, because I fully expect him to learn his profanity at home.