The song is by 50 Cent and the remix features Olivia. The song is produced by Hi-Tek. The song also samples the song "Silly, Wasn't I?" by Valerie Simpson from her self-titled 1972 album for its beat. It also constantly makes references to Biz Markie's "Just a Friend" chorus.
The beat in the song is actually different from the real version by 50 Cent. In the movie, the "Best Friend" instrumental is substituted by "The Bridge Is Over" by KRS-One.