Time flies when you're in love! Demi Lovato [1] and Wilmer Valderrama [2], who have spent the last week on the slopes, celebrated six years together on Jan. 10, and the couple took to Instagram [3] to share a series of adorable posts. "Six," Demi captioned a snuggly snap in bed, later posting an aww-inducing montage of six photos (one for every year they've been together [4]) and an adorable mountaintop kiss (read: kiss attempt). Though their relationship has been filled with its fair share of challenges [5], we're glad to see that Demi and Wilmer are more in love than ever — hey, Wilmer, where is the ring? Keep scrolling to see their anniversary pictures, and then check out even more of their sweetest Instagrams [6].