What that F*&k is going on?

In general, I don't censor myself in front of my children because I think if we censor ourselves, our kids become much more into saying curse words simply because they are taboo.  So, I don't call my kids curse words or anything (or anyone else), I do let the occasional "son of a bitch" or the equivalent.  Anyhow, today, while playing Wii, my son, A, said, what sounds like "what the f*ck is going on?"  I asked him repeatedly what he was saying as I couldn't quite place what he was saying.  I asked him who says that and he said, "sometimes you do."  So, I thought he must not be saying what I thought I'd heard because I don't say that phrase (sure, I use all the words in that phrase, but not that actual phrase).  Anyhow, I talked to him about how he shouldn't say those words because it upsets other people.  He was fine with that and settled for the "Holy Guacamole!" instead. 

About 10 minutes later, C is saying "I ____ you."  Now I can't figure out if it was "I five you" or "I f*ck you."  Oy vey!  I'm going to go with "I five you" because she followed it up with "I six you." 

So, if you see my kids and hear them saying some select words, I apologize in advance.