Hold on one second. Let's get this straight. Marty is your kid, not mine.
5 seconds sound clip from the Back to the Future Part II movie soundboard.
You can hear this line at 00:47:35.087 in the Blu-ray version of the movie.
Quote context
[...]
- Did you get kicked out of another boarding school?
- What the hell do you care? We can afford it.
- The least we can do with all that money is provide a better life for our children.
- Hold on one second. Let's get this straight. Marty is your kid, not mine.
- And all the money in the world wouldn't do jack shit for that lazy bum.
- Stop it, Biff. Just stop it.
- Look at him. He's a butthead, just like his old man was.
- Don't you dare speak that way about George. You're not even half the man he was.
[...]