Everyone knows kids pick up phrases, inflection, and often times, bad words from their parents.
Here's a recent conversation from our house indicating that just this very thing is occuring.
A few days ago
Sam: Blah blah blah, dangit!
Me: Hey, where'd you hear that?
Sam: (smiling sheepishly) From you...
Me: Well it doesn't sound very nice coming from you. I guess I need to work on not saying it anymore, huh?
While he was frantically searching our living room
Sam: Where is the freakin' DVD?!
Me: What'd you just say, buddy?
Sam: (again with the sheepish smile) Where is the freakin' DVD?
Me: I don't want you saying that anymore.
Sam: Well...I guess you just need to work on not saying it.