What IS that?

Pookie apparently has a thing for "older" ladies.  Pookie managed to grab the attention of a rather cute little girl a week or so ago.  Pookie and I were attending an event at a relatives house.  There were a lot of people from the husband's side of the family there.  Kids were running amok, it was great!  But this one little girl thought Pookie was just the bee's knees.  She wanted to hold him, and play with him.  I must say, she was an excellent helper.  As the day went on, she announced that Pookie had done peepee's in his pants.  Considering it had been a while sense I changed him, I felt that she was spot on.  So, I got my self all set up, plunked Pookie on the floor and proceeded to change him.  Of course the little girl wanted to get in on the action.  As I was going along, she piped up, "what is that?".  Um, ya, about that.  I'm thinking to myself, what in god's green earth do I say?  Should I go the anatomically correct route?  Or should I go with something else.  The last thing I want is the parent to come up to me asking what I have been teaching the little girl.  Ugh.  Luckily for me, the little girl saved the day.  She piped up "is that his private parts?", you betcha!  I got out of that one by the skin of my teeth!