Super-fun day in the Harris-Burtka household!

Neil Patrick Harris and fiance David Burtka celebrated the first birthday of twins Gideon Scott and Harper Grace on Wednesday.

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"Things I dig: our twins Gideon and Harper, who are one year old today!" How I Met Your Mother star Harris, 38, Tweeted. "They are glorious. So proud to be their Papa."

Harris gushed of love Burtka: "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."

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Son Gideon and daughter Harper may be wearing baby formalwear soon enough: Their proud papas confirmed long-held plans to marry in June, right after gay marriage was legalized in New York State.

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"David and I did propose to each other, but over five years ago!" Harris explained. "We've been wearing engagement rings for ages, waiting for an available date."

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