- What's this?
- That's the number at the sorority house.
- Fellatio?
- Yeah, it's the new exchange, 'FE'.

15 seconds sound clip from the Black Christmas (1974) movie soundboard.

You can hear this line at 00:51:23 in the Blu-ray version of the movie.

Quote context

[...]

- Mr. Harrison's daughter is missing.

- And now at the house where she lives, the other girls are getting obscene phone calls.

- Don't you think we ought to look into it?

- Well, Lieutenant, I guess, sure.

- Thank you, Lieutenant.

- Yeah, thanks Ken.

- Sergeant Nash, could I speak to you for a minute?

- Yeah... sure, Lieutenant.

- What's this?

- That's the number at the sorority house.

- Fellatio?

- Yeah, it's the new exchange, 'FE'.

- Yeah, fellatio. One of the girls that was in this afternoon gave it to me.

- She gave it to you?

- Yeah.

- Nash, I don't think you could pick your nose without written instructions.

(MOCKING SNICKERING LAUGHTER)

- I know. Something dirty, ain't it?

[...]