Where does the pee come out of if there's no penis?

Drazil's post today has totally inspired this one so be forewarned!

Once upon a time I was driving my cute little Tommy around - he was probably 6ish, but that's a total guess.  And he had recently walked in on me going to the bathroom one too many times... where it finally truly occurred to him that I did not have a penis (I guess maybe he was a bit younger??)

Anyway we're driving along and thank the heavenly lord above he's in the backseat so he could not see my face, but the conversation went something like this.

Tommy: Seriously, you really don't have a penis?

Me: Yup, girls don't have penises, only boys do.

Tommy: okay - but where does the pee come out?  It's got to come out somewhere.  (did I mention that Tommy is a little engineer in the making - he must understand how things work)

Me: There's a little hole down there, it's just not at the end of a penis.

Tommy: A hole?  Hmmmm.  Ridgely's a girl.  (Ridgley was our lab)

Me: yup, Ridgley's a girl (Okay, where is this going?)

Him: She has like a tiny little penis and that's where the pee comes out of, right.

Me: (oh god) um.. yup.. that's right, but it's not a penis.

Him: But so girls have something like that?

Me: uh... sure.  yeah, it's something like that, but not exactly - you know - most girls don't have fur.

Him: Okay, got it.  Can I see yours.

Me:  uh, that would be a no.  I'll see if I can find a picture for you.

That satisfied him.  Kept the car on the road and got him to school on time.  I never did find a book to show him.