Credit: Instagram

We just can't even with how fast the kiddos of Teen Mom are growing up, y'all. It seems like a mere five seconds ago that Bentley Edwards, Leah Shirley, and Sophia Abraham (the real stars of MTV, to be honest) were bursting into this world and capturing our hearts.

Credit: Maci Bookout on Instagram

Nowadays, these sweet children are entering whatever the childhood equivalent of middle aged-dom is. Believe it or not, all three of these Teen Mom tots are in Kindergarten (sob, how did this happen?) and what’s even crazier? They're starting to lose their teeth.

Yep, the Tooth Fairy is making her very first visit to the great city of Chattanooga to pay a visit to Maci Bookout's son, Bentley, because (OMG!) he lost his very first tooth!

Maci took to Instagram to share the exciting news by posting a collage of adorable snapshots of Benny showing off a toothy grin. "Benny lost his first tooth at school today! FINALLY! #bigkid,” she wrote.

Look at that cheesy smile, guys! Plus, what’s even more impressive, Bentley already has a new tooth to replace the old one. The little dude wastes no time!

Can you believe Maci's sweet son has reached this big kid milestone? Sound off below.