The couple married in 2017 but first met 18 years ago on a blind date.
Uploading an adorable fresh-faced throwback photo of the pair to his Instagram page, Texas-born Jim wrote a lengthy gushing message giving his followers the lowdown on their romantic history.
He wrote: “Babies that were born the day I met Todd Spiewak turn 18 years old today; happy birthday to them, and happy 18th blind-date-set-up anniversary to Todd.
“Our intuitive friends, Tami and Oonie, put us together and, on November 15th, 2002, we played pool (huh?) at Slate on 21st street; we sang Karaoke (again, huh?) at Sing Sing on Avenue A, and then we went to Robbie’s birthday party at… some gay bar on the east side (that part makes sense to me).
“Todd walked me to the 1st Ave L train stop and, as we said goodbye, I knew we would be seeing each other again – which ended up being two nights later, when we went to see Michael Moore’s “Bowling for Columbine” at the Union Square AMC – because nothing says “let’s start a life-journey together” better than a divisive documentary (why couldn’t we just go see “My Big Fat Greek Wedding”, like every other new couple in 2002?)
“That said, we both loved the movie and talked about it at Patsy’s Pizzeria (may the Union Sq location Rest In Peace) afterward.
“My life changed completely and completely for the better. Love wins! ❤️ 🌈”
Jim’s fans were elated at his anniversary news, with many flooding the comments section with their own messages of congratulations.
The loved-up pair have previously scooped the German Bravo Otto Award for Hot Couple.
Producer Todd meanwhile is no stranger to starring on screen, having featured in movie A Kid Like Jake.
He also produced Young Sheldon, a prequel to The Big Bang Theory, which began in 2017.
Young Sheldon stars Iain Armitage as the pint-sized genius who’s battling his way through high school pleasantries and features the voiceover of TBBT star Jim Parsons.