The 5 year old boy in this cartoon was naturally curious about his body and asked his daddy to tell him what a certain part was.  When his daddy told him what it was, he came to the logical conclusion that this is where pee originates!

Again, my oldest nephew makes it into my comics.  Grandma and grandpa were visiting when he was 4 years old.  Grandma always calls grandpa “honey”.  It’s only understandable that a young child would assume that’s his name!