Listen, darling, I know you fairly well. You're keeping something from me. What is it?
5 seconds sound clip from the Dead of Night (1945) movie soundboard.
You can hear this line at 00:37:55.834 in the Blu-ray version of the movie.
Quote context
[...]
- Sorry, I didn't mean to say that.
- Peter, what's the matter with you? You've been edgy for days.
- Yes, I know. I haven't been sleeping too well.
- Oh, it doesn't matter. Forget it.
- Listen, darling, I know you fairly well. You're keeping something from me. What is it?
- It's getting me down. I'd really rather not talk about it.
- You'll feel much better if you do. It's no good bottling things up, you know.
- The only thing to do is to try not to look in it at all.
- But in a queer sort of way it fascinates me.
[...]

 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)