“Lo Vas A Olvidar” is Billie Eilish’s first single released in 2021, and at the same time her first collaboration with the Spanish singer ROSALÍA. This song is part of the soundtrack of Euphoria, a series of the American television network, HBO.

The collaboration had been announced since 2019, date on which ROSALIA noted that only Billie’s verses were missing to finish the production. In January 2021, a musical insider shared a tweet with the name of the collaboration, along with the release date.

The official announcement was made on January 19, 2021, through different publications on their social networks, and a commercial spot of Euphoria, in which the song could be heard in the background.