Thought this funny!
2 boys at school, one asks the other "what's a penis?" the other boy says "I don't know? I'll go home and ask my Dad"
The boy goes home and asks "dad, what's a penis?" his dad smiles and takes down his pants! and responds "this is a penis son, in fact! this is what you call a PERFECT PENIS"
Next day the boys see each other at school. "so did you ask your dad what a penis is?" "yes", the boy proceeds to take his pants down, "this is a Penis! and if it was just 4 inches shorter it would be a PERFECT PENIS"