Don't talk with your mouth full.
3 seconds sound clip from the Labyrinth (1986) movie soundboard.
You can hear this line at 00:45:32 in the Blu-ray version of the movie.
Quote context
[...]
- What do you think? Which shall we choose out of these two ugly characters?
- Oh, I'm sorry. I was just wondering which door to choose.
- It's no good asking him. He's as deaf as a post.
- Don't talk with your mouth full.
- I'm not talking with my mouth full!
- Wait a second. I can't understand you.
- Ah.
- It is so good to get that thing out.
[...]