Having read Jimmy Cagney's autobiography he said that when they filmed the scene where he and Jack Lemmon finally meet on ship and Cagney asks him how long he's been aboard at which Lemmon says ''14 months'' they could not keep from cracking up and loosing it so they could not look themselves in the eyes for that line. You can see how they are looking down for those lines to avoid eye contact.
sharecagney's autobiography [James Cagney, "Cagney by Cagney," 1976] is a must-read for any fan.
i love this anecdote:
"I was driving down Coldwater Canyon in Beverly Hills, came to a red light, and saw Bogart there in a brand new Porsche or some singularly fancy sports car.
I have to preface this by saying Bogie had a nervous habit of picking his nose wherever he was. So there I saw him, stopped for this red light, in this very fancy open car, picking his nose with great industry, little realizing I was watching him.
The next day I wrote him this little note:
In this silly town of ours,
One sees odd primps and poses;
But movie stars in fancy cars,
Shouldn't pick their famous noses.
I never got an answer."