We both know how hard you've worked.
4 seconds sound clip from the The Last Man on Earth (1964) movie soundboard.
You can hear this line at 00:30:20 in the Blu-ray version of the movie.
Quote context
[...]
- Is that what you really think, or just what you'd like to think?
- I cannot accept half-baked theories that sell newspapers. I'm a scientist, not an alarmist.
- You're whistling past the graveyard.
- Is that a commentary on my work at the lab?
- We both know how hard you've worked.
- I just can't accept the idea of universal disease.
- Uncle Ben, you promised us card tricks.
- All right, Kathy. Who can resist that face?
- All right. Card tricks. Card tricks.
[...]