There is a moment in “The Philadelphia Story” that was, according to Cary Grant and Jimmy Stewart, improvised. It’s the scene when Jimmy Stewart comes to Cary Grant’s house and he’s drunk. And Jimmy Stewart hiccups; that was thrown in. You can see that Jimmy’s amused and Cary looks down and he was amused that Jimmy was amused. They almost broke up!
Peter Bogdanovich
THE GREATEST SCENE OF ALL TIME.