"Part-Time Lover" is a song by American R&B singer and songwriter Stevie Wonder, released as the first single from his twentieth studio album, In Square Circle (1985). The song reached number one on the Billboard Hot 100, R&B, dance, and adult contemporary charts, becoming Wonder's final number one hit to date. The song's simultaneous chart successes made Wonder the first artist to score a number-one hit on four different Billboard charts. The song was also released as a special 12" version. Lyrically, it tells the story of a man who is cheating on his wife with a mistress, only to find out in the end that his wife is cheating on him as well. "Part-Time Lover" also reached number three on the UK Singles Chart thanks in large part to a performance by Wonder on Top of the Pops in late 1985. The song featured R&B singer Luther Vandross singing the ad-libs and backing vocals, in addition to Syreeta Wright and Philip Bailey of Earth, Wind and Fire. Wonder earned a Grammy Award nomination for Best Male Pop Vocal Performance in 1986, for the song. Wonder is noted in the liner notes of the 4-CD set Hitsville USA: The Motown Singles Collection Volume 2 1972-1992 as describing the music for the song as an ode to "You Can't Hurry Love" and "My World Is Empty Without You", both by the Supremes, former Motown labelmates of Wonder.