Why?

Why is mommy's belly so big? Why does she want me to kiss her belly and keeps calling it baby? Why did mommy and daddy laugh when I pointed to daddy's belly and said baby? Why do they call the play room the baby's room? Why are there a bunch of non-pink clothes in the other room? Why did daddy get my baby car seat down from the attic? What is all this talk about baby brother? I'm so confused.