About you and him? Yes, but you know that.
2 seconds sound clip from the Dead of Night (1945) movie soundboard.
You can hear this line at 01:21:54.184 in the Blu-ray version of the movie.
Quote context
[...]
- Sorry, but I can't bear anyone touching him.
- Oh, that's all right. Forget it.
- Say, I sure like to know how you pulled that gag.
- What gag? 'Cause I don't quite follow you.
- Well, just now before you came in.
- You know, for a moment, I could've sworn it was the dummy speaking. And me a pro.
- Hold on, don't let's start that all over again.
- About you and him? Yes, but you know that.
- You wouldn't... You wouldn't ever do that, would you?
- Say, are you nuts or something?
- How in heck could I team up with Hugo? He's yours, isn't he?
- Yes, that's right, he's mine.
- What kind of heel do you think I am anyway that I'd try to steal another guy's act?
[...]

 Dead of Night (1945)
 Dead of Night (1945)  Phantom of the Opera (1943)
 Phantom of the Opera (1943)  Scooby-Doo, Where Are You! (1969)
 Scooby-Doo, Where Are You! (1969)  Halloween III: Season of the Witch (1982)
 Halloween III: Season of the Witch (1982)  Knight Rider (1982)
 Knight Rider (1982)