The Cardboard Lover (1928) (Blu-ray)

A ditzy American girl visiting Monte Carlo is hired by a tennis champ to be his "cardboard lover"--to pretend to be in love with him so he can teach his two-timing fiancée a lesson and win her back. What he doesn't realize is that the girl isn't pretending; she actually is in love with him, and she sets out to win him for herself.