Soon-to-Be Big Sister Has Adorable Hissy Fit Over Baby's Gender Reveal

It's impossible to know what to expect when you're expecting, and the baby's sex can be one of the biggest surprises. One thing's for sure, no one has been quite as surprised as this soon-to-be big sis.

What happens when two adorable little girls learn the sex of their third sibling on National Siblings Day? If the little ladies in this video are any indication, a few reactions are possible.

A new YouTube video showcases two sweet little sisters reacting as their parents, Shaun and Heidi, reveal the sex of their new baby on the way. The girls are each given a cupcake (yum!) and asked to break into it—if they see blue inside, that means they'll welcome a little brother. Pink inside the cupcake means they'll have a sister. 

More: The Rising Popularity of Gender Cakes

One of the sisters breaks into her cupcake, sees the blue interior and happily announces that she's going to have brother. Her sister, on the other hand? Well, let's just say she doesn't take the news quite as well. 

See for yourself below. This video is just straight up adorable.

More: Mom Has Hilarious Reaction to Gender Reveal