G.I. Blues (1960)
Serviceman Tulsa McLean (Presley) is an American soldier stationed in West Germany who has plans to open a nightclub when he returns home.
To raise money for the venture he makes a $300 bet that he can spend the night with Lili (Juliet Prowse), a frosty Frankfurt cabaret dancer. Then just as Tulsa realises that his feelings for Lili are changing, she finds out about the bet.
Prowse adds a lot of class and Elvis sings a bunch of songs, including the title track and Wooden Heart.
In his first film after finishing with military service, Elvis was dating both Juliette Prowse and Leticia Roman at the time. The Prowse romance was apparently pretty serious for a while.