The pair, who have been married for close to 23 years, attended amfAR's star-studded 21st Cinema Against AIDS Gala in France on Thursday evening, May 22. They were on hand for the big moment when the proposal took place on the red carpet.
Movie producer Oscar Generale (Casino Jack) got down on one knee at the event, offering a ring to his girlfriend, actress and model Denny Méndez. Travolta flashed a thumbs-up and Preston, 51, clapped while Méndez, 35, accepted the proposal and began to cry.
Generale, who is working with Travolta on the upcoming animated flick Gummy Bear the Movie, was wearing a full tuxedo when he popped the question. His future wife, once Miss Italy, was in a gorgeous black gown.
Preston and Travolta also looked equally stunning. She wore a red lace Oliver Tolentino Couture gown with diamond jewelry, while Travolta rocked a navy tuxedo.
Preston and Méndez embraced before the foursome sat down for dinner together at the event.
The beauty queen and her husband-to-be began dating in 2012.