What the heck?!!

Nate has been doing a decent job with potty training.  I know you're probably not interested in all the sordid details so I will spare you, but for the sake of my story I will say that he still has a small accident in his diaper once or twice a day.  At this point we don't really know how much of this has to do with his disease and how much is just him being a stinker, but the fact that he wakes up with a dry diaper every morning makes me wonder sometimes if he is just having too much fun in life to bother telling me he needs to go potty.  Anyway, when we discover he's had an accident we'll usually say something along the lines of, "Nate, you wet your diaper!  You need to remember to tell us when you have to go."  And until last week he would always admit fault and promise to do better next time, but now he has changed tactics.  Now when we say, "Nate, you wet your diaper!" he will give us this totally incensed look like he's every bit as surprised and appalled as we are and then give us one of these choice replies:

"What??!!  What??!  What is going on here??!!"
"What?!!  Is that bad or something?"
"I don't know what peeping is.  What does peeping mean?!" (He calls wetting himself "peeping".)
Or my personal favorite, "What the HECK!??!"