just put your lips together...

"Slim - You know you don't have to act with me, Steve.
You don't have to say anything, and you don't have to
do anything. Not a thing. Oh, maybe just whistle.
You know how to whistle, don't you, Steve?
You just put your lips together and... blow."

One of my always movie,
"To have and have not",
for the lines...

for the two of them!