Neil Patrick Harris' Kids Are the Most Adorable -- and Stylish -- Kindergartners Ever on First Day of School

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Too cute!

Neil Patrick Harris and husband David Burtka's 5-year-old twins, Gideon and Harper, recently had their first day of kindergarten, and couldn't look more adorable for the occasion. Harris shared a photo of the two giving a fierce pose before they headed off to school, Harper killing it in a pair of black shades and boots, while Gideon also looked dapper in suspenders and his own pair of stylish sunglasses.

"Kindergarten fits these two well. #firstdayofschool," Harris captioned the priceless pic.

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The 43-year-old actor got a little sentimental about the milestone day on Wednesday, tweeting, "The twins' first day of kindergarten. So many feels: excited, nervous, giddy, wistful. But mostly proud. Can't wait to see who they become."

In June, Harris and 41-year-old Burtka celebrated Harper and Gideon's preschool graduation.

Harris has talked about his children's different personalities before, including Harper's adorably dramatic ways.

"They're pretty quintessential boy and girl," Harris shared during his appearance on Inside the Actors Studio last February. "Harper is a girl, girl, girl. Girl. She wears mermaid outfits and has falls in her hair, and you have to announce her when she comes down the staircase. And then when you do, she slowly comes down the stairs acting all, like, 'Oh, me?'"

"[Gideon] loves trucks and construction and he likes superheroes," he added.

The family of four recently had another big occasion to celebrate -- Harris and Burtka's two-year wedding anniversary on Tuesday. The two tied the knot on Sept. 6, 2014, in Italy.

"Two years ago, @dbelicious and I got hitched. Best. Decision. Ever.," Harris sweetly Instagrammed on the big day.

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Last September, Harris talked to ET about the key to a successful marriage.

"You got to ebb and flow," the former How I Met Your Mother star said. "The relationship changes. The definition of it changes."

"In our relationship, communication is super important," he explained. "Good friends of ours said, 'You need to talk it out,' and if that means raising your voice, you need to raise your voice. Know what you're talking about. Know where you're standing as opposed to letting stuff build up, I guess."

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