Neil Patrick Harris and David Burtka have been together for 17 years. Here's a timeline of their relationship.

The pair co-penned a 2012 essay about their relationship for Out magazine, in which Harris wrote about his first impression of Burtka.

"I ran into my friend Kate one day and she was with this brooding, James Dean–type guy in a leather jacket who gave me the head nod and then turned away," he wrote. "I assumed he was Kate's boyfriend and said, 'Nicely done.' And she said, 'David? He's not playing on my team, but he has a boyfriend.'"

In the same piece, Burtka added that his long-distance relationship at the time "was sort of on the rocks."

The two hung out for the first time at an "American Idol" viewing party thrown by a mutual friend, and Harris wrote that he "couldn't take my eyes off" Burtka.

Harris and Burtka first spent time hanging out with each other platonically.

"We began hanging out with other people, and we had a lunch or so, but nothing romantic," Burtka wrote for Out. "I thought he was adorable, though, with these amazing blue eyes that are just hypnotizing to me."

Burtka eventually broke up with his long-distance boyfriend, and a week later, he and Harris went to see a movie as their first date. After that, the two became nearly inseparable.

"We started hanging out every single night, and after three months, it was just nonstop," Burtka added. "We talk on the phone at least eight times a day and text at least 25 times a day."

When Harris took on the role of Barney Stinson on the CBS classic "How I Met Your Mother," which first aired in 2005, the couple moved to Los Angeles, California, together so he could shoot the show.

"I assumed the show would be a short chapter," Harris told Architectural Digest in 2015. "But the plan was always to come back to New York when the show ended and raise our family."

But the sitcom ran for nine seasons and nearly 10 years, coming to an end in 2014.

Harris publicly came out as gay in an exclusive 2006 interview with People magazine amid "speculation and interest in my private life and relationships."

"... I am happy to dispel any rumors or misconceptions and am quite proud to say that I am a very content gay man living my life to the fullest and feel most fortunate to be working with wonderful people in the business I love," he said.

Harris wrote in the Out magazine essay that Burtka proposed to him on the street corner where they first met. The two were riding in a limousine to a casino 45 minutes out of town when Burtka requested they stop.

"... David wanted to stop for some reason that I didn't quite get," Harris wrote. "I thought he wanted to get some booze or something."

"And then he got on one knee and proposed, and I was so freaked out by it that I said, 'Yes,' but I didn't know what it meant," he added.

A year after Burtka popped the question to Harris, the "How I Met Your Mother" star also proposed to his "better half" on Valentine's Day, according to their essay.

"The callus on my right hand is long-formed ... I'm dying to move over to the other hand," Harris wrote about getting married. "I'd also like to call him my husband."

The duo welcomed fraternal twins — Gideon Scott and Harper Grace — on October 12, 2010.

In a 2012 interview with Oprah Winfrey, Burtka said the pair worked with a surrogate and egg donor to conceive the twins.

"Two eggs, two embryos, one of mine, one of his, and two took," he explained.

Harris wrote for Out that "children were always talked about" and they agreed that they didn't want to have kids "super late in the game."

Burtka added they named Gideon after an artist they liked and Harper after the author of one of their favorite books, "To Kill a Mockingbird."

Overs five years after their original proposal, Harris and Burtka publicly confirmed their engagement a day after New York's state Senate passed the Marriage Equality Bill on June 24, 2011.

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

On September 6, 2014, Burtka and Harris tied the knot in Italy during "an intimate ceremony surrounded by their close friends and family," the actor's representative told People magazine.

The magazine reported that the two were officiated by longtime "How I Met Your Mother" director Pamela Fryman and that Elton John performed live at the reception.

On September 8, 2014, Harris tweeted a photo of the two from their wedding day with the caption, "Guess what? @DavidBurtka and I got married over the weekend. In Italy. Yup, we put the 'n' and 'd' in 'husband'."

On April 1, 2015, Burtka tweeted a photo of Harris kissing him on the cheek in celebration of 11 years together.

"Happy 11 year anniversary to @ActuallyNPH Without him I'd be lost! He makes me so happy!" Burtka wrote.

At Food Bank's Can-Do Awards Dinner in April 2017, Burtka told New York Daily News that he had recently given up drinking because he's not "one of those people that can just have one drink or two drinks."

"It just didn't mix well with me anymore," he said. "I didn't like the way I was acting and I think it was affecting me and I thought, 'You know what? I owe it to myself. I owe it to my kids, to be there, 100%.'"

The two have spoken about the ups and downs of their relationship. Burtka penned for Out in 2012, "I don't want people to think we're a perfect couple."

"A relationship is work and it changes. And you go with the changes," Burtka added. "It's more good times than bad times, but it's not always good. You have to overcome those issues and move on."

In May 2017, Burtka told Life and Style magazine that he and Harris attend couples counseling to keep their relationship strong.

"We go to couples therapy," Burtka said. "Not that there's anything wrong, but it's nice to sort of just talk to someone who is a mediator. That's helped our relationship."

On September 6, 2018, Harris posted a throwback photo of the couple's wedding with a caption that started with, "Four years ago today. How time flies — especially when you have someone special to share it with. After 14 years, two children, and thousands of adventures together, I've never been happier."

The same day, Burtka posted a photo on Instagram of the duo, writing that he's "so very proud of us."

"Being in a relationship is hard work. There are many stresses to juggle within these 14 years," Burtka continued. "We have dealt with kids growing up, new jobs, the media, moving and even dogs pooping on the rugs."

Harris and Burtka's kids turned 8 years old on October 12, 2018, and the Broadway actor posted a photo on Instagram of his two children with balloons.

"Eight years ago David and I got the two greatest presents imaginable. Eight years later we are still counting our blessings," he started the caption. "Happy Birthday, Gideon and Harper. You rock our worlds."

In September 2020, the pair commemorated their sixth wedding anniversary on social media.

Harris posted a photo from their 2014 wedding on Instagram and wrote that he's had "no regrets."

"Six years ago. Perhaps the happiest day of my life," Harris started the caption. "Since then, thousands of memories. No regrets. Thank you, David, for both creating and rocking my world."

Burtka similarly celebrated their marriage on Instagram by posting a photo of the two dancing at their wedding with a caption that included, "I can't believe you stuck around after all these years of me annoying you."

In early 2021, Burtka went into the hospital for an intensive spinal surgery that lasted over seven hours.

Harris posted a photo of Burtka wearing a hospital gown and neck brace and holding two thumbs up.

"David is recovering from spinal surgery. It was fairly intensive, took over seven hours, but he's in good spirits and doing well," Harris wrote in the caption. "It's one of the scarier, more hopeless feelings - hoping for the best, trying not to fear the worst, waiting a call with news. Thankfully, all went according to plan."