The 35-year-old "That'70s Show" star said their relationship is based on a "beautiful" friendship, reported ET online.
"You know, we've been best friends for about six years. We haven't necessarily been dating for six years, but we have six years of friendship, and it's been, it's been beautiful. All I did was love her exactly when she needed me to love her. And you know, we just stay honest. That's it," Wilmer said.
The "Confident" singer has previously said that the two started dating when she turned 18.