It's been about three-and-a-half years since Blake Shelton and Gwen Stefani revealed that they were an item. The pop star has perhaps been feeling nostalgic, as she recently shared a trip down memory lane on Instagram.

An old photo that People reports was taken on the set of The Tonight Show Starring Jimmy Fallon shortly before the pair confirmed their relationship, shows Shelton and Stefani with smiles on their faces. Stefani captioned the photo with the hashtags "#timeflies" and "#bestie," as well as a heart emoji.

Shelton and Stefani went public with their relationship in early November of 2015, shortly before the 2015 CMA Awards, after rumors that they were dating began circulating online. At the time, the two were both coaches on The Voice, and both recently divorcedStefani and her husband Gavin Rossdale split up in August of 2015, while Shelton and wife Miranda Lambert ended their marriage in July of that year.

Despite public speculation about if and when Shelton and Stefani will get engaged, the pair, according to Stefani, feel "zero pressure" to take another walk down the aisle. However, both are in it for the long haul.

“This is something that I feel like is meant to be,” Shelton says. “I’ve learned more from Gwen Stefani as a human being and how to grow as a human being than I have from anybody ever in my life. Anybody. She’s everything that you could hope a human being could be.”

Stefani has three children from her marriage to Rossdale. They and Shelton and Stefani recently attended the premiere of the UglyDolls movie, in which Shelton voices a character, together.

See Pics of Blake Shelton, Gwen Stefani and Her Boys at UglyDolls Premiere: