Blake Shelton and Gwen Stefani were all smiles during their duet performance of “Go Ahead And Break My Heart” on Sunday Night’s (5/22) Billboard Music Awards, even though the two were singing a breakup song. Blake told Ellen, “We kinda did laugh a few times. There was moments where it was like ‘Wow, we’re singing this song like we’re gonna break up and we’re not breaking up right now, you know, this just seems kinda weird.'”