Peter Cetera & Cher - "After All"

How can two divas record a song together, yet never record it together?  I don't know, but you should ask Peter Cetera and Cher.  Their 1989 hit "After All" became a #1 hit, yet the two never were in the same room when the song was recorded or performed.  Each musician recorded their vocal tracks separately, and a producer mixed the song.  "After All" was part of the soundtrack to "Chances Are" and even got nominated for "Best Original Song" at the 1990 Oscar Awards.  Did Cher and Cetera show up to perform the song together?  Nope.  Peabo Bryson and Melissa Manchester performed the song instead.  Divas.