After Tonight is a song featured on Mariah Carey's 1999 album "Rainbow." Originally, the song was supposed to be a duet with singer Luis Miguel (who was dating Mariah at the time).
Due to Mariah and Luis not being musically compatible with each other (due to Mariah's high vocal range), they were forced to repeatedly re-record the song numerous times. Reportedly, a frustrated Luis took scissors to the tape of the song and sent the pieces of it back to producer David Foster, but Foster denies the tape was sent to him in pieces and maintains that Luis & Mariah's duet fizzled for musical reasons.
In the end, the album version of the song featured only Mariah's vocals. The song remains unreleased and it's unlikely that it would be released due to Mariah not being involved with Sony\Columbia Records & the end of her relationship with Luis.