Neil Patrick Harris and husband David Burtka couldn't be prouder of their twins, Gideon and Harper.
The two both took to Instagram to wish their kids a happy sixth birthday, sharing adorable pics of the stylish brother-and-sister duo.
"Gideon and Harper turn 6 today!" Harris wrote on Wednesday alongside snaps of the two going down a water slide. "Happy birthday to these big, bold, brave, bright, beautiful bundles of bountiful blessings. Boom. #balliteration @dbelicious and I love you kids SO much! #grateful."
WATCH: Neil Patrick Harris, Nick Lachey, and 6 More Super Adorable Celeb Kid Back-to-School Pics!
A photo posted by Neil Patrick Harris (@nph) on
Burtka took to Instagram a day later to also gush about their twins.
"Happy Birthday to the most loving, fearless and most adventurous eaters I know!!" Burtka wrote. "@nph And I love you Gideon and Harper!"
A photo posted by David Burtka (@dbelicious) on
Harris and 41-year-old Burtka married in Italy in September 2014. They welcomed their twins in October 2010 via a surrogate mother.
Last month, Gideon and Harper celebrated another important milestone -- their first day of kindergarten.
Kindergarten fits these two well. #firstdayofschool
A photo posted by Neil Patrick Harris (@nph) on
"So many feels: excited, nervous, giddy, wistful," Harris, 43, tweeted about the big moment. "But mostly proud. Can't wait to see who they become."
See more adorable celeb kid back-to-school pics in the video below!