It grows like a cold sore from the lips.
3 seconds sound clip from the The Little Shop of Horrors (1960) movie soundboard.
You can hear this line at 00:16:24.441 in the Blu-ray version of the movie.
Quote context
[...]
- So how come I'm all of a sudden so wonderful?
- Five bees? One for each finger?
- Did you say I was getting a two dollar raise?
- Correct, my very excellent Seymour. Indeed.
- Don't you know what you did?
- Oh, boy! Look at that! It grew. It's almost a foot long.
- It grows like a cold sore from the lips.
- Oh, hello young pretty ladies. What can Gravis Mushnick do for you?
- Well, we saw your sign outside.
- So we thought we'd come in and take a look.
- That makes four people today who come in just to look at it.
[...]