But when we were saying goodbye, he took me in his arms and kissed me and I knew.

9 seconds sound clip from the The Best Years of Our Lives (1946) movie soundboard.

You can hear this line at 02:03:05.225 in the Blu-ray version of the movie.

Quote context

[...]

- Are you sure he doesn't love her?

- Of course I am.

- Did he tell you? Did she?

- No.

- So you just jumped to conclusions.

- He doesn't love her, he hates her. I know it. I know it.

- Who are you? God? How did you get this power to interfere in other people's lives?

- Is Fred in love with you?

- Yes.

- You've been seeing him?

- Only once. Today.

- Oh, it was all perfectly respectable.

- But when we were saying goodbye, he took me in his arms and kissed me and I knew.

- And you think a kiss from a smooth operator like Fred, you think that means anything?

- You don't know him. You don't know anything about what's inside him. Neither does she. His wife.

- That's probably what she thought when she married him. A smooth operator with money in his pockets. But now he isn't smooth any longer, and she's lost interest in him.

- Whereas you're possessed of all the wisdom of the ages.

[...]