Left shoulder.
5 seconds sound clip from the Jaws (1975) movie soundboard.
You can hear this line at 00:08:49 in the Blu-ray version of the movie.
Quote context
[...]
- Got the blue balls, crabs, and the seven-year itch.
- Left, right, left, right, left.
- What are you trying to do to my beloved Corps?
- You are dumb, but do you expect me to believe that you don't know left from right?
- Then you did that on purpose. You wanna be different.
[...]