Let's put it this way. She might have fooled me, but she didn't fool my mother.
6 seconds sound clip from the Psycho (1960) movie soundboard.
You can hear this line at 01:11:30 in the Blu-ray version of the movie.
Quote context
[...]
- Let's just say, just for the sake of argument, that she wanted you to gallantly protect her.
- You'd know that you were being used.
- You wouldn't be made a fool of, would you?
- But I'm not a fool. And I'm not capable of being fooled, not even by a woman.
- Well, this is not a slur on your manhood.
- Let's put it this way. She might have fooled me, but she didn't fool my mother.
- Well, then your mother met her. Could I talk to your mother?
- No. As I told you, she's confined.
- Yes, but just for a few minutes. That's all.
- There might be some hint that you missed out on.
- You know, sick old women are usually pretty sharp.
[...]