Richard Gere celebrated his 75th birthday with hyped-up fans at a masterclass hosted by Cartier at the Venice Film Festival and revealed some behind-the-scenes on the filming of his 1990 hit movie “Pretty Woman” which catapulted Julia Roberts into star status.

Reacting to a clip of his steamy piano scene with Roberts, Gere laughed and blushed about his palpable chemistry with the actor.

“No chemistry,” he laughed. “I mean, this actor and this actress, obviously, had no chemistry between them… I haven’t seen that in a long time, too. It was a sexy, sexy scene.”

Gere then went on to share that the scene had been improvised. “This was never in the script. … We didn’t know how we would use it later. It ended up being integral to the film,” said Gere, who also joked that he “was playing a character that was almost criminally underwritten. It was basically...