The "Deadpool" star took to Instagram to share a cute pic of the pair together — and in the caption, he joked they'd once been sweethearts.
"I don’t usually post about ex-girlfriends. But Betty’s special. Happy Birthday to the one and only, @bettymwhite," Reynolds, 42, wrote.
In the photo, the two actors sweetly hold hands during a 2010 appearance on "The Tonight Show with Jay Leno."
Reynolds played White's grandson in the 2009 comedy "The Proposal," and the two have been pals ever since.
Last year, the actor helped White ring in her 96th birthday by sharing a hilarious image of his "Deadpool" character celebrating with a martini and a hot dog next to a portrait of White enjoying her own frankfurter.
"Happy Birthday to the one and only @bettymwhite! Cheers to another year of 'Tinis and Weenies!" he joked.
The six-time Emmy winner, whose entertainment career has spanned more than 75 years, credited her longevity to her upbeat attitude — and her love of vodka and hot dogs.
The "Golden Girls" alum also shared some simple advice to anyone wanting to follow in her fabulous footsteps.
"Enjoy life," White said. "Accentuate the positive, not the negative. It sounds so trite, but a lot of people will pick out something to complain about, rather than say, 'Hey, that was great!' It’s not hard to find great stuff if you look."
We couldn't agree more. Happy birthday, Betty!