On Saturday, Loughlin shared a black and white snap of the two sitting in the back of a car, with the actress waving at the camera and her husband flashing a peace sign.
"Happy 20th Anniversary @mossimog !" Loughlin captioned the photo.
The couple met in 1995 and married in 1997. They share two daughters, Isabella, 19, and Olivia, 18, and Giannulli also has a 26-year-old son, Gianni, from a previous marriage.
"If they only knew then what they know now," Stamos wrote, dating the shot, "Circa 82." He also used hashtags to reference his role as Blackie on General Hospital and Loughlin's role as Jody from The Edge of Night.
Loughlin also sent a congratulatory tweet to Stamos last month after he announced his engagement to actress Caitlin McHugh.
"No one deserves a happy ending more than
And no one deserve a happy ending more than you my old friend. Congrats to you both. Sending so much love?❤️? https://t.co/6tTatI3q64— Lori Loughlin (@LoriLoughlin) October 23, 2017
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