Try blowing slower. Now you're getting it.
7 seconds sound clip from the Happy New Year, Charlie Brown! movie soundboard.
You can hear this line at 00:10:14.214 in the VHS version of the movie.
Quote context
[...]
- I wonder when my Sweet Baboo is going to ask me to the party.
- I am not your Sweet Baboo! And I wouldn't invite you to a garage sale!
- Isn't he the cutest thing? (2)
- You blow up a balloon this way. OK, now let's see you do it.
- Try blowing slower. Now you're getting it.
- Here, I've got another type of balloon. Watch.
- Well, are you taking me to the party or not?
- Anyway, I'll be playing the piano at the party.
[...]