That's not why you didn't marry Caroline. The real reason is, you're in love with someone else.
8 seconds sound clip from the Desk Set (1957) movie soundboard.
You can hear this line at 01:14:00 in the Blu-ray version of the movie.
Quote context
[...]
- Anyway, so I asked him to look her up, and, you know, keep her from being lonely, and he did.
- And then I got the Dear John letter.
- What are you talking about? They're very happily married.
- If she never writes him a letter, he'll never know the difference.
- That's not why you didn't marry Caroline. The real reason is, you're in love with someone else.
- Who?
- My sock... My socks match today. Look.
[...]