Josh Radnor meets his 'How I Met Your Mother' son David Henrie for first time

Josh Radnor finally met his TV son David Henrie after nearly two decades.

The How I Met your Mother co-stars, who never actually shared the screen over the acclaimed sitcom’s decade-long run, took to their respective Instagrams to document the legendary moment.

The picture featured the pair smiling for the camera as they stood side by side in a hallway.

“Found my father. Finally,” Henrie quipped in the caption, adding a hashtag of the show’s initials.

Meanwhile, Radnor - a musician – referenced the 1970 Cat Stevens song Father and Son in his caption through a portion of the lyrics detailing the son’s desire to break away and shape a new life for himself.

The iconic romantic comedy series ran from 2005 to 2014, with Radnor’s character Ted Mosby telling his son, Henrie’s character Luke, the story of his young adult life in New York City with his friends and how he eventually met and married his mother.

But Henrie only ever shared the screen with Lyndsy Fonseca, Ted’s daughter, for just a handful of scenes set in the year 2030.

Amazingly, all their reaction and lines were shot ahead in 2006 to ensure that the teenage characters would not age as the pair sat on the sofa and listened to their father, voiced by Bob Saget off-screen, recount the pre-determined story in excruciating detail.

Fans of the show joined in on the fun in the comments section, with one asking Henrie, “Has he told you about meeting your mother yet? I’m sure it’s a very short and to the point story.”