Shelton opened playing the guitar, wearing a sharp black blazer and shirt with jeans. Stefani, of course, brought the sparkle and bling in a gorgeous, sheer gown.
The two locked eyes throughout the entire performance, essentially forgetting the rest of the audience was there.
The pop singer and country crooner first premiered their song on "The Voice." With lyrics like, “Why don’t you go ahead and break my heart? / Why are you waiting, is it way too hard? / If moving on is what you want to do / Why don’t you do it?" the song offers a very personal look at the pair's relationship.
Stefani and Shelton began dating in 2015 after separately going through divorces. The two went public with their relationship when both coaching on "The Voice," and have since written songs about each other.
"If you have followed my career even a little bit in my life, you know what has happened with me in the last, gosh, eight or nine months," Shelton told Entertainment Tonight in March. "I can put my life experience, whether it’s a divorce or my new girlfriend, whatever those experiences are, whatever things that are happening in my life, I have an outlet for them."