Love in the Afternoon is a 1957 American romantic comedy film produced and directed by Billy Wilder which stars Audrey Hepburn and Gary Cooper. The screenplay by Wilder and I.A.L. Diamond is based on the Claude Anet novel Ariane, jeune fille russe (trans., Ariane, Young Russian Girl), which previously was filmed as Scampolo in 1928 and Scampolo, ein Kind der Strasse (trans., Scampolo, a Child of the Street) in 1932, the latter with a script co-written by Wilder. Wilder was inspired by a 1931 German adaptation of the novel Ariane directed by Paul Czinner. Wikipedia
Ariane Chavasse: They're very odd people, you know. When they're young, they have their teeth straightened, their tonsils taken out and gallons of vitamins pumped into them. Something happens to their insides! They become immunized, mechanized, air-conditioned and hydromatic. I'm not even sure whether he has a heart. Michel: What is he? A creature from outer space? Ariane Chavasse: No. He's an American.