How time flies. Neil Patrick Harris and longtime partner David Burtka commemorated the one-year birthday of their adopted twin boy and girl this week.

Tweeted NPH yesterday: "Things I dig: our twins Gideon and Harper, who are one year old today! They are glorious. So proud to be their Papa."

Aww. The How I Met Your Mother star is such a sap.

The 38-year-old star added: "And I'm in awe of, and so grateful for, David Burtka. He is, in my humble opinion, the greatest dad in the history of ever."

Aww again.

Gideon and Harper are certainly lucky to have two adoring fathers in Neil Patrick Harris and David Burtka, who announce their engagement this summer upon the passage of New York State's gay marriage equality law. Happy birthday, kids!

[Photo: Fame Pictures]