When to stop prompting.

I sat down with one of my students the other day for some one on one work and his task was to draw a picture of a person. Our conversation:

Me: I want you to draw a picture of someone. You can pick anyone you want, you, your mom, me, your Grandpa anyone.

Student: Me.

So he starts to draw. First 5 different circles "heads" until he got the one that looked right. Then two eyes and a mouth and he stopped.

Me: What about arms? Do you have arms?

He draws two arms coming out of the head and stoops again.

Me: Do you have legs?

He draws two legs coming out of the head and remembers he has hair and draws that too.

Me: That's a great picture of you, it looks just like you. Anything else you want to add? (I'm thinking maybe ears, nose?)

Student: OH WAIT! I forgot my penis!

Me trying my hardest not to laugh: Oh, okay. Go ahead draw your penis.

So he does.

Seriously???
I've never had a student draw their penis and I've had many students draw pictures of people.
This particular student is pretty bright and often likes to test the limits and try to get reaction out of me. I'm pretty proud of myself for not busting out laughing or showing the surprise in my face.

Now I know to stop prompting while I'm ahead. I mean, I could tell that it was a person even without the nose, ears, or penis.