When you're a 5-year-old kid, you know that a lot of times your parents can try to troll you just to get you to do things. Remember the times your mom or dad said they'd eat your cereal if you didn't and you panicked and ate it all? Yeah, they bluffed.
No wonder kids often doubt if adults are telling the truth or not. When this boy in this video is told by his mom that he's gonna be a big brother, his reaction in only natural.
But oh so freaking damn cute!