I can't believe you did that! Oh, God, man, what did you do that for?
7 seconds sound clip from the The Greatest (1977) movie soundboard.
You can hear this line at 00:15:16.633 in the Blu-ray version of the movie.
Quote context
[...]
- But I wanted him to meet your family and friends, sir.
- I know you want everything to go nice and smooth for yourself. Right? You understand?
- Cash, wait a minute. What are you doing?
- Man, this thing is phony gold-plated, and it ain't worth a damn.
- I can't believe you did that! Oh, God, man, what did you do that for?
- It wasn't worth a shit anyway.
- No, you got those hands too low. Now get them up. Hustle, hustle! And the hands, the hands!
- Cassius, don't lean back like that!
- What, you prefer this sucker to hit me in the head? Come on, sucker, try it.
[...]