<P> When Wells recorded her vocal she sang over the song's outro with a huskiness evoking the line delivery of Mae West: Wells would recall: "I was only joking but the producers said' Keep it going, keep it going' ." </P> <P> "My Guy" became the biggest hit ever for Wells, Motown's first female star, and reached the top of the Billboard Hot 100 pop singles chart on 16 May 1964 . The song led the Cashbox magazine R&B chart for seven weeks . "My Guy" was also Wells' last hit single for Motown, except for duets she recorded with label mate Marvin Gaye . An option in her recording contract let Wells terminate the contract at her discretion after she reached her twenty - first birthday on May 13, 1964 . Encouraged by her ex-husband, Wells broke her Motown contract and signed with 20th Century Fox in hopes of higher royalties and possible movie roles . However, Wells' career never again reached the heights it had at Motown, and she never again had a hit single as big as "My Guy". </P> <P> Her version of the song was used in the film "More American Graffiti" (1979) </P> <P> In the United Kingdom, "My Guy" peaked at number five in June 1964 . </P>

What film is the song my guy in