The song was originally released on April 2, 2021, as the ninth track on Lovato's seventh studio album Dancing with the Devil... the Art of Starting Over.

[5] At the end of March 2021, Lovato revealed the featured artists for her seventh studio album, Dancing with the Devil... the Art of Starting Over, by posting snippets of the collaborations on her social media accounts, including the song with Grande.

[11][12] Following the release of Dancing with the Devil... the Art of Starting Over, "Met Him Last Night" was sent to contemporary hit radio in the United States on April 13, 2021, as the fourth and final single from the album.

[14] "Met Him Last Night" was described by Billboard as "a dark, twisted fantasy about chilling with the devil and finding out that, well, he's kind of a funny, chill dude who might be relationship material", containing the lyrics "I've seen the devil, yeah, I met him last night/ One conversation, now he's spendin' the night," which an "urgent" Lovato sings "in a couplet that clearly has a much deeper meaning about flirting with disaster.

[16][17] In reviews of the album, "Met Him Last Night" was referred to by NME as a "dark and atmospheric electro bop",[1] and Neil McCormick from The Daily Telegraph highlighted the song as not only "a flirty duet in which the seductive title character is the Devil" that "succeeds in both acknowledging the dangers of the high life and making fun of them at the same time," but that it reflects the way in which Lovato's album as an entirety pleasurably "succeeds in grappling with serious matters without jettisoning any of the lightness, melodiousness, nimble rhythms and sugar-high hooks of her pop genre.