Neil Patrick Harris Commemorates Special Milestone With David Burtka With Heartfelt Message

The couple are celebrating their anniversary together.

It's a big day for Neil Patrick Harris and David Burtka!

The happy couple is celebrating nearly two decades together, and they each had a few sweet words to say to each other in honor of the moment.

First up, Harris shared a selection of photos from throughout the years, starting with a solo shot of Burtka leaning against the corner of a leather sectional, holding a rose to his nose, which was followed by a series of photos of the two together.

"19 years ago today I went on my first date with this man. Single greatest decision of my life," the How I Met Your Mother actor wrote. "Happy Anniversary, David Burtka! You are the ultimate, most astonishing roller coaster ride, and I can’t get enough. Thank you for believing in me, for believing in yourself, for believing in us. You’re the best husband, the best father, and my best friend. Here’s to a bazillion more awesome adventures!"

Burtka was quick to comment, "Awwe babe. I love you so much," and followed up with a sweet tribute to their relationship of his own.

"HAPPY 19th YEAR ANNIVERSARY!! I can’t believe it (actually I can… ) The good times have have outweighed weighed the bad enormously," he wrote on his own account. "I am beyond grateful to take this wonderful journey with you. As we grow as people our relationship gets stronger. Thank you for being you, putting in the work & making us the best we can be. I am honored and ecstatic to be by your side. Love always, David."

Along with the message, he shared two sweet photos of the couple, one from several years ago, with Harris leaning his head against Burtka's shoulder, his arm slung over the other, as the two sat in a restaurant booth, and one that was seemingly taken with a grainy filter, where Burtka leaned his head against Harris' as the two stood outside.

The couple, who share twin daughter and son Harper and Gideon, 12, will celebrate their ninth wedding anniversary on Sept. 6 of this year.