The YouTuber couple took to Instagram to share their touching letters.
"Oh Scottie, what was life before you even?" Kryz wrote, featuring a family photo from her maternity shoot. "Our first big blessing is now two years old. Every day, you make our hearts sing. We love you so very much, Scott Knoa. Happiest birthday!"
Slater, meanwhile, posted a collage of photos from when Scottie was a newborn. Aww.
"To my dearest baby boy, it’s been two years already?" Slater wrote. "Time flies so fast. Although I want to hold on to 'Baby Scottie' for as long as I can, I also cannot wait to see the man that you will become. Watching you grow is (and always will be) the greatest joy of my life."
Kryz and Slater recently welcomed their second child, Sevi Young, in May. Scottie is now a kuya!
Happy birthday, Scottie!
MORE ON KRYZ UY AND SLATER YOUNG: