Birthday Boy

A little boy goes up to his mom and says "mommy can take a shower with you?"
The mom says "no", so the boy says "please it's my birthday".
"Ok" says the mom "just don't look up or down".
"Ok I promise" says the boy.
But as soon as they're in the shower the boy looks up and says "mommy what are those?"
The mom says "those are my headlights"
"oh" says the boy. Then he looks down and says "mommy what is that?"
So she says "that's my bush".
"oh" said the boy.
Later the boy goes up to his dad and says "daddy can take a shower with you?"
and the dad says "no". "Please it's my birthday".
"ok" said the dad "just don't look down".
"ok I promise" said the boy.
But as soon as they're in the shower the boy looks down and says "daddy what's that?"
so the dad says "that's my snake".
"oh" said the boy.
That night the boy says "mommy, daddy can I get in bed with you I had a bad dream." "no" say his parents.
"Please it's my birthday".
"Ok" said his parents "just don't look under the covers"
"ok I promise" said the boy.
But as soon as he is in the bed he looks under the covers and screams
"mom turn your head lights there's a snake in your bush!"