- I remember your honeymoon very well. You and she on a little sailboat. The True Love, wasn't it?
- That's right. How did you know?

9 seconds sound clip from the The Philadelphia Story movie soundboard.

You can hear this line at 00:12:51 in the Blu-ray version of the movie.

Quote context

[...]

- He'll introduce you to the Lords as intimate friends of Junius.

- Dear old Junius.

- Now, this Tracy Lord. She know you?

- You might say Miss Lord and I grew up together.

- You might also say you were her first husband.

- Yes, you might.

- Holy mackerel, what goes on here?

- I remember your honeymoon very well. You and she on a little sailboat. The True Love, wasn't it?

- That's right. How did you know?

- I was the only photographer whose camera you didn't smash. You were terribly nice about it. You threw it in the ocean.

- Oh, one of those, huh?

- Yes, I had the strange idea our honeymoon was our own business.

- Incidentally, he paid for all the cameras. I got a nice little letter of apology too.

[...]