Part-time lover is Stevie Wonder's 9th (out of 10 so far) US #1 in 1985 following the success of I just called to say I love you earlier. The song hit the #1 spot in four different Billboard charts simultaneusly - a first ever! In UK it reached #3 and charted all over the globe. Luther Vandross, Stevie's ex-wife Syreeta Wright and Earth, Wind & Fire's Philip Bailay are providing the backup vocals. Puerto Rican Bobby Valentin brought the song to Latin charts the year after.