He'll never know because I stay kissing-sweet... the new Dazzledent way? Now, really.

8 seconds sound clip from the The Seven Year Itch (1952) movie soundboard.

You can hear this line at 01:15:39 in the Blu-ray version of the movie.

Quote context

[...]

- Tell me, Dazzledent toothpaste... It's funny. You know, I don't think I ever tried it.

- You should. It's excellent toothpaste.

- Is it?

- Oh, yes. I use it myself.

- Oh, then you do recommend it. I mean, off the record, between friends.

- Definitely.

- It costs only a few pennies more than ordinary toothpaste, but a recent survey shows that eight out of 10 oral hygienists...

- Now you sound like a commercial again. If I believed every commercial I heard...

- You can believe this one, every word of it.

- What's that you say on the program?

- He'll never know because I stay kissing-sweet... the new Dazzledent way? Now, really.

- It's true. I'll prove it to you.

- Well?

- My faith in the integrity of American advertising is somewhat restored.

- You see?

- However, before I go to all the trouble of switching brands, I want to make absolutely certain.

[...]